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Personal Finance & Loans

1031 Exchange Boot Liability Estimator

Quantify cash and mortgage boot exposure in a 1031 exchange so you know how much gain stays tax-deferred.

Date & Time

2-2-3 (DuPont) Shift Schedule Planner

Generate a rolling 2-2-3 rota showing day/night balance, hours, and rest stretches based on your start date and shift length.

Technology & Coding

3D Print Time & Cost Estimator

Forecast runtime, filament usage, and energy expenses for an FDM 3D print so you can quote jobs with confidence.

Technology & Coding

3D Print Time Estimator

Estimate FDM print duration from model height, layer height, and average print speed to plan your production schedule.

Personal Finance & Loans

401(k) Employer Match Calculator

Project total 401(k) contributions by combining your deferrals with the employer match formula.

Date & Time

4-3-3 Shift Rotation Scheduler

Build a 4-3-3 shift rota, measure day/night balance, and flag gaps against night-duty preferences.

Personal Finance & Loans

529-to-Roth Transfer Eligibility Calculator

Confirm SECURE 2.0 eligibility and map the annual rollover schedule before shifting leftover 529 savings into a Roth IRA.

Health & Fitness

A1C to eAG Calculator

Convert an HbA1c laboratory result into estimated average glucose (eAG) or translate daily glucose readings back to A1C.

Web & Marketing

ABM Webinar Pipeline Payback Calculator

Quantify the pipeline surplus or shortfall from an ABM webinar versus your target coverage multiple.

Education & Learning

Academic Probation GPA Recovery Planner

Determine the term GPA needed in upcoming credits to climb back to your target cumulative GPA after probation.

Finance & Business

Accounts Receivable Turnover Calculator

Compute accounts receivable turnover by dividing net credit sales by average accounts receivable.

Science & Engineering

ACH Target Gap Calculator

Convert airflow and room dimensions into actual air changes per hour and see how far you are from your ventilation goal.

Health & Fitness

Acute:Chronic Workload Ratio

Monitor weekly training spikes by comparing the current load to the rolling average from prior weeks.

Web & Marketing

Ad Inventory Floor Price Stress Test

Stress test header bidding floor prices against bid forecasts to quantify revenue drag, fill risk, and optimization levers.

Date & Time

Add Business Days

Calculate the future or past business date by skipping weekends—ideal for due dates, SLAs, and project schedules.

Date & Time

Add Weeks to Date Calculator

Find the calendar date that results after adding a specified number of weeks to a starting date.

Personal Finance & Loans

Adjustable-Rate Mortgage Reset Payment Calculator

Estimate the new monthly payment when your ARM resets and compare it with the current payment.

Web & Marketing

Affiliate Ads Break-even Calculator

Calculate the maximum cost per click you can pay for traffic while breaking even on affiliate commissions.

Web & Marketing

Affiliate Clawback Buffer Calculator

Set aside the right reserve to absorb affiliate clawbacks without starving reinvestment.

Web & Marketing

Affiliate Landing Page Profit Gap

Compare affiliate commission revenue with paid traffic spend to spot RPM gaps on landing pages.

Date & Time

Age Calculator

Enter your birth date to determine your precise age in years, months, days, hours, and minutes.

Date & Time

Age in Days Calculator

Convert your age in years to an approximate number of days, accounting for leap years with the 365.25-day average.

Date & Time

Age in Hours

Estimate how many hours you have lived based on age in years.

Date & Time

Age in Months Calculator

Convert an age expressed in years to total months. Enter the years and press Calculate.

Date & Time

Age in Weeks Calculator

Convert age in years to weeks.

Science & Engineering

Agrivoltaics Lease Split & Yield Impact Calculator

Blend crop yield changes with solar lease income to compare per-acre revenue, required lease sharing, and yield sensitivity for agrivoltaics.

Technology & Coding

AI API Usage Break-Even Pricing

Translate per-token costs and overhead into a minimum viable AI API price that meets your target gross margin.

Technology & Coding

Estimate the run-rate of serving LLM completions or chat responses at scale. Enter your average prompt and completion token counts, expected monthly request load, published per-1K token rates, and any per-token surcharge for GPUs, orchestration, or guardrail services to see the all-in cost projection.

Technology & Coding

AI Inference GPU Cost Parity Calculator

Contrast self-hosted GPU spend with managed API pricing to pinpoint the breakeven cost per 1,000 tokens.

Technology & Coding

AI Trust & Safety Moderation Staffing Forecaster

Turn flagged-item volume, automation deflection, and handling time into required moderator FTEs and monthly spend.

Home & DIY

Air Changes per Hour Calculator

Determine ventilation effectiveness by calculating how many times the air in a room is replaced each hour.

home-diy

Air Conditioner BTU Calculator

Estimate cooling capacity needed for a room.

Lifestyle & Travel

Airline Miles Value Calculator

Compare cash fares against award tickets to reveal the dollar value of your airline miles.

Lifestyle & Travel

Airport Lounge Membership Value Calculator

Quantify the net annual value of lounge memberships or premium cards after guest access, statement credits, and visit costs.

Lifestyle & Travel

Airport Lounge Pass Break-even Tracker

Compare an annual lounge membership with pay-as-you-go access. Enter the yearly pass price, what you would pay per visit (including guest fees), how many guests you usually bring, and the value you assign to food and drinks to learn the break-even visit count.

Lifestyle & Travel

Airport Lounge Payback Calculator

Work out how many airport lounge visits you need for a membership or premium card to beat buying day passes, including guests and annual travel credits.

Health & Fitness

Blood Alcohol Elimination Time Calculator

Estimate how long it takes for your blood alcohol concentration (BAC) to reach zero based on an average elimination rate.

Health & Fitness

Altitude Acclimatization Schedule Calculator

Design a staged ascent plan by capping daily sleeping altitude gains and inserting rest nights for safe acclimatization.

Web & Marketing

Amazon PPC Incremental ROI Calculator

Separate incremental sales from cannibalized revenue to gauge Amazon PPC profitability, TACoS, and budget headroom.

Health & Fitness

Ambulatory Blood Pressure Load Calculator

Calculate the percentage of 24-hour ambulatory readings above your daytime and nighttime blood pressure thresholds.

Conversions & Units

Amp-hours to Watt-hours Converter

Convert a battery's capacity in amp-hours to energy in watt-hours using its voltage.

Date & Time

Annual Work Hours Calculator

Estimate total work hours in a year after vacation days.

Finance

Annuity Net Present Value Calculator

Calculate the net present value of an ordinary annuity by discounting equal cash flows and subtracting the upfront investment.

Technology & Coding

API Rate Limit Capacity Planner

Translate provider rate limits into the maximum number of concurrent clients your service can support without throttling.

Technology & Coding

API Rate Limit Planner

APIs often restrict how many requests you can send in a given window. This planner divides the allowed requests by your clients and window length to compute the minimum seconds to wait between calls for each worker. Enter the provider's limit, the window duration in seconds, and the number of parallel clients to see the recommended delay.

Conversions & Units

APR to Flat-Fee Lending Translator

Convert merchant cash advance or flat-fee offers into an equivalent APR, factor rate, and remittance schedule.

Math & Statistics

Arc Length of a Circle

Calculate the distance along a circle's edge from its radius and central angle.

Math & Statistics

Arithmetic Series Sum Calculator

Find the sum of the first n terms in an arithmetic series using the formula S = n/2 × (2a₁ + (n−1)d).

Math

Aspect Ratio Calculator

Determine the width-to-height ratio of a rectangle.

Finance & Business

Asset Turnover Ratio Calculator

Compute the asset turnover ratio by dividing net sales by average total assets.

Lifestyle & Travel

Astro Tourism Trip Planner

Blend clear-sky odds, lunar illumination, trip length, and budget to project astronomy getaway success and cost.

Education & Learning

Attendance Requirement Calculator

Enter total class sessions and the required attendance percentage to find allowable absences.

Home & DIY

Attic Fan Size Calculator

Estimate the attic fan CFM and intake vent area needed from square footage, height, and climate adjustment.

Personal Finance & Loans

Auto Loan Payment Calculator

Calculate the monthly payment on an auto loan using the principal, annual interest rate, and loan term.

Math

Average Speed Calculator

Compute average speed from distance traveled and time taken.

Web & Marketing

B2B Keyword Intent Profit Forecaster

Project net profit from ranking on a high-intent B2B keyword using search volume, CTR, conversion, and deal profit inputs.

Lifestyle & Travel

Backpack Weight Ratio Calculator

Check what percentage of your body weight your backpack represents for safer travel.

Lifestyle & Travel

Baggage Overweight Fee Calculator

Calculate how much you'll pay for overweight luggage based on airline fee per kilogram.

Personal Finance & Loans

Balance Transfer Break-Even Calculator

Estimate how many months it takes for a balance transfer offer to pay for its upfront fee.

Home & DIY

Balcony Solar ROI Calculator

Project payback period and lifetime savings for plug-and-play balcony solar kits using production, tariffs, and export credits.

Conversions

Banana Equivalent Dose Converter

Compare radiation exposure to the dose from eating bananas.

Technology

Bandwidth Delay Product

Estimate in-flight data on a network link.

Lifestyle & Travel

Bank Fee Dispute Refund Estimator

Estimate how much of your recent bank fees you can recover based on courtesy policies, success odds, and tenure.

Finance

Bank Treasury Liquidity Coverage Ratio

Apply Basel III haircuts to HQLA buckets and compare against 30-day stressed outflows to monitor daily LCR compliance.

Health & Fitness

Bariatric Surgery Out-of-Pocket Planner

Estimate bariatric surgery costs owed after deductibles, coinsurance, out-of-pocket caps, and optional HSA offsets.

Health

Basal Metabolic Rate

Estimate daily calories burned at rest using the Mifflin-St Jeor equation.

Technology

Base64 Encoded Size Calculator

Determine output size when data is Base64 encoded.

Home & DIY

Baseboard Trim Length

Determine the total feet of baseboard trim required after subtracting door and window openings.

Technology & Coding

Battery Charge Time

Estimate how long a battery needs to reach full charge from its capacity, charger current, and efficiency.

Science & Engineering

Battery Demand Charge Avoidance Calculator

Quantify how a commercial battery trims utility demand charges, estimate annual savings, and project a simple payback based on installed cost per kWh.

Science & Engineering

Battery Energy Arbitrage Margin Calculator

Evaluate the gross margin per cycle from buying off-peak power and selling during peak windows.

Technology

Battery Life Calculator

Estimate device runtime from battery capacity and draw.

Technology

Battery Life Estimator

Approximate device runtime from battery specs.

Science & Engineering

Battery Round-Trip Efficiency Calculator

Compute round-trip efficiency by aligning charge intake, delivered discharge energy, and auxiliary losses.

Technology

Battery Runtime Calculator

Estimate battery runtime from capacity and load.

Science & Engineering

Battery State of Charge (SOC) Calculator

Track battery state of charge by combining nominal capacity, initial SOC, and coulomb-counted amp-hours.

Science & Engineering

Battery State of Health (SOH) Calculator

Assess battery state of health by comparing measured capacity and resistance against rated specs.

Science & Engineering

Battery Storage Frequency Regulation Revenue Planner

Model gross and net frequency regulation revenue for a battery portfolio with ISO clearing prices and dispatch assumptions.

Math & Statistics

Bayes' Theorem Calculator

Update prior probabilities with new evidence using Bayes' theorem to support diagnostic testing, risk analysis, and data science modeling.

Math & Statistics

Bayesian A/B Sample Size Planner

Work out the traffic per variant required for a Bayesian conversion test given priors, lift targets, and credibility.

Math

Bayesian A/B Test Sample Size

Estimate sessions per variant for a Bayesian proportion test using desired uplift, credibility, and probability to beat control.

Conversions

Beard-second to Meters

Translate beard-seconds into meters.

Math & Statistics

Benford's Law Compliance Calculator

Paste transaction amounts or other positive numbers to estimate how closely their first digits align with the Benford distribution.

Science & Engineering

Bifacial Solar Gain Estimator

Quantify the bifacial boost on annual production by blending DC capacity, site-specific yield, surface reflectivity, and rear irradiance exposure. Use it to validate plant models and communicate expected kWh gains with prospects and asset owners.

Other

Bill Split per Person

Split a bill evenly with an optional tip.

Date & Time

Billable Hours to Units Converter

Convert billable hours to 6-minute billing units.

Technology

BIM Download Time Calculator

Estimate download time for large BIM models.

Technology & Coding

Binary Search Steps Calculator

Determine how many comparisons binary search needs to find an item in a sorted list of size n.

Technology

Binary to Decimal Converter

Convert a binary number to decimal.

Technology & Coding

Binary to Decimal Converter

Convert binary strings of 0s and 1s into base-10 numbers.

Other

Binge-Watching Time Calculator

See how long your next marathon session will take.

Lifestyle & Travel

Birthday Paradox Probability Calculator

Discover how likely it is that people in a group share a birthday using the classic probability puzzle.

Technology & Coding

Bitcoin Mining Break-Even Electricity Rate

Find the electricity price your bitcoin miner must pay to break even after accounting for hash rate, power draw, network competition, pool fees, and non-power operating expenses.

Technology & Coding

Bits Required for Number Calculator

Determine how many bits are needed to encode a non-negative integer in binary.

Conversions

Bits to Bytes Converter

Convert bits to bytes.

Personal Finance & Loans

Biweekly Mortgage Payment Calculator

Find your biweekly mortgage payment based on principal, interest rate, and loan term using 26 payments per year.

Health

Blood Alcohol Content Estimate

Approximate blood alcohol concentration using drink count, body weight, and elapsed time.

Health

Blood Donation Recovery Planner

Estimate fluid replacement, iron needs, and rest days after whole blood, plasma, or platelet donation.

Conversions

Blood Glucose mmol/L to mg/dL

Convert mmol/L glucose readings to mg/dL instantly with medical-grade precision and see reference ranges for fasting and post-meal targets.

Health & Fitness

Blood Volume Estimate

Approximate total blood volume using average liters per kilogram.

Health

BMI Calculator

Calculate your Body Mass Index (BMI) from metric height and weight to evaluate weight status categories.

Health

BMI Prime Calculator

BMI normalized to the upper healthy limit of 25.

Health & Fitness

Basal Metabolic Rate Calculator

Estimate daily calories burned at rest.

Personal Finance & Loans

BNPL APR Calculator

Estimate the annual percentage rate of a BNPL plan by comparing total fees to the purchase amount and repayment term.

Home & DIY

Board Feet Calculator

Calculate lumber volume in board feet using thickness, width, and length.

Home & DIY

Board Foot Calculator

Determine the board feet of a piece of lumber from its thickness, width, and length in inches.

Lifestyle & Travel

Board Game Night Duration Planner

Estimate total event length by combining average playtime, rules explanations, breaks, and table turnover.

Health & Fitness

Body Adiposity Index Calculator

Estimate body fat percentage using hip circumference and height.

Health & Fitness

Body Composition Adjusted BMI Calculator

Estimate a body-composition-aware BMI that tempers the classic formula with measured body fat percentage. Ideal for athletes, coaches, and clinicians who need a quick lean-mass comparison alongside standard BMI.

Health & Fitness

Body Fat Mass Calculator

Find the mass of body fat based on total weight and body fat percentage.

Health & Fitness

Body Fat Percentage Calculator

Estimate body fat percentage using the Deurenberg formula with weight, height, age, and gender inputs.

Health

Clinical BMI Uncertainty Calculator

Compute body mass index with propagated measurement uncertainty and WHO classification.

Health & Fitness

Body Surface Area (Du Bois)

Estimate body surface area (BSA) using the Du Bois formula with weight in kilograms and height in centimeters. Enter the values and press Calculate.

Health & Fitness

Body Surface Area (Haycock) Calculator

Estimate body surface area from height and weight using the Haycock formula.

Health

Body Surface Area (Mosteller)

Estimate BSA from weight and height.

Science & Engineering

Boiling Point at Altitude

Estimate water's boiling temperature based on elevation.

Lifestyle & Travel

Book Page Count Estimator

Estimate book pages from total word count.

Education & Learning

Bootcamp vs. Master's ROI Calculator

Contrast the payback period and 10-year net value of a coding bootcamp versus a master's degree using salary uplift.

Web & Marketing

Bounce Rate Calculator

Determine the percentage of single-page visits on your site.

Home & DIY

Box Volume Calculator

Find the capacity of a box from its length, width, and height. Enter the three dimensions in meters to calculate the volume in cubic meters.

Finance

Break-Even Units Calculator

Estimate units to break even.

Finance & Business

Break-Even Units Calculator

Determine how many units you must sell to cover fixed and variable costs before turning a profit.

Date & Time

Break Time Planner

Plan how many minutes of break you should take in a workday.

Home & DIY

Brick Cost Calculator

Estimate the total price of bricks based on quantity and cost per brick. Enter the values and press Calculate.

Home & DIY

Brick Count Estimator

Estimate how many bricks are needed to build a wall.

Conversions & Units

BTU to kWh Cooling Cost Calculator

Convert HVAC capacity from BTU/h to kWh and estimate hourly and monthly operating costs with demand charges.

Conversions & Units

BTU to kWh Converter

Enter energy in BTU to convert to kilowatt-hours.

Conversions & Units

BTU/hr to Watts Converter

Convert heating or cooling capacity from BTU per hour to watts.

Finance & Business

Budget Variance Percentage

Measure how far actual spending deviates from your budget as a percentage.

Lifestyle & Travel

Business Class Award Value Optimizer

Calculate cents-per-point value for premium cabin awards and compare against cash fares and rebates.

Date & Time

Business Days Between Dates

Find how many business days fall between two dates, excluding weekends.

Technology

Bytes to Kilobytes Converter

Convert raw byte counts to kibibytes (binary KB) with smart formatting, plus guidance for sizing files, memory, and transfer limits.

Health

Caffeine Half-Life

Estimate remaining caffeine over time.

Health & Fitness

Caffeine Limit by Weight Calculator

Estimate a conservative daily caffeine maximum based on your body weight using a 3 mg/kg guideline.

Finance

CAGR Calculator

Compute the compound annual growth rate between an initial and final value.

Nutrition

Calorie Burn Equivalence Calculator

Convert calories from meals into the minutes of exercise required to burn them off.

Health & Fitness

Calorie Deficit Daily Intake Calculator

Calculate your daily calorie intake after applying a chosen deficit. Enter maintenance calories and desired deficit, then press Calculate.

Health

Calorie & Macro Target Planner

Translate your daily calorie target into precise grams of protein, carbs, and fats per day and per meal.

Health & Fitness

Calorie Surplus Weight Gain Calculator

Estimate potential weight gain from extra calories consumed.

Health

Calories Burned (MET) Calculator

Estimate calories burned using activity MET value, body weight, and duration.

Health & Fitness

Swimming Calories Burned Calculator

Enter your body weight, swim duration, and stroke MET value to estimate calories burned.

Health & Fitness

Calories from Fat Percentage Calculator

Determine what percentage of calories come from fat.

Lifestyle & Travel

Candle Burn Time

Estimate how long a candle will burn by dividing its wax weight by the average burn rate.

Science & Engineering

Carbon Capture 45Q Credit Revenue

Convert captured CO₂ volumes and credit rates into annual 45Q tax credit revenue for storage and utilisation projects.

Health & Fitness

Cardiovascular Risk (Framingham) Calculator

Estimate 10-year cardiovascular disease risk using a simplified Framingham-inspired formula.

Home & DIY

Carpet Cost Calculator

Calculate the total cost of carpet materials by multiplying room area by the price per square foot.

Finance & Business

Cash Conversion Cycle Benchmark Gap Calculator

Calculate your cash conversion cycle, benchmark it against an industry target, and see how many days you are ahead or behind on working capital.

Finance & Business

Cash Conversion Cycle Calculator

Calculate the cash conversion cycle (CCC) to understand how many days cash is tied up from purchasing inventory to collecting customer payments. Enter DIO, DSO, and DPO to receive a formatted breakdown.

Lifestyle & Travel

Cat Age in Human Years

Convert your cat's age to the equivalent human age using a veterinary guideline.

Personal Finance & Loans

CD Ladder Optimizer

Plan a cash ladder that balances yield and liquidity by projecting how much your certificates of deposit will grow once each rung has matured. Enter the total cash you will deploy, the number of CDs, the annual percentage yields for the shortest and longest terms, and the maturity of the final rung to see the blended ladder value.

Web & Marketing

CDN Offload Rate Calculator

Quantify how much traffic your content delivery network serves versus origin by combining request and byte telemetry.

Education & Learning

CEFR Study Hours Estimator

Estimate additional study hours required to progress from your current CEFR language level to a target level. Use 0 for no level, 1 for A1 up to 6 for C2.

Home & DIY

Ceiling Fan Size Calculator

Recommend fan blade span based on room area.

Home & DIY

Ceiling Paint Needed Calculator

Calculate how many gallons of paint are needed for a ceiling by multiplying area by coats and dividing by paint coverage.

Conversions

Celsius to Fahrenheit

Convert Celsius temperatures to Fahrenheit.

Conversions & Units

Celsius to Kelvin

Easily convert temperatures from degrees Celsius to Kelvin for scientific calculations or everyday use.

Education & Learning

Certification Renewal Planner

Work out the credits, study pace, and budget needed to renew your certification before it expires.

Health & Fitness

Continuous Glucose Alert Fine-Tuning

Set CGM high and low alerts based on your typical fasting and post-meal readings, then customize buffers to reduce nuisance alarms.

Health & Fitness

CGM Annual Net Cost Estimator

Estimate yearly out-of-pocket costs for continuous glucose monitoring after insurance coverage.

Health & Fitness

CGM Sensor Buffer Budget Calculator

Plan monthly and annual cash buffers for continuous glucose monitor sensors after insurance reimbursement.

Technology & Coding

Character Count Calculator

Paste or type any text to instantly see how many characters it contains.

Nutrition

Artisan Cheese Maturation Time Calculator

Balance the microclimate in your cheese cave with the flavor targets of each wheel to forecast when it will be ready to wrap, ship, or plate. This tool translates temperature and humidity logs into a realistic maturation timeline for small-batch artisans.

Math & Statistics

Chi-Square Goodness of Fit Calculator

Enter observed and expected values for up to three categories to calculate the chi-square statistic for a goodness of fit test.

Technology & Coding

CI/CD Testing Budget Calculator

Combine pipeline frequency, runtime, runner pricing, and storage costs to forecast a monthly CI/CD testing budget.

Health & Fitness

Circadian Shift Work Planner

Plan a recovery window that supports melatonin release and alertness by calculating when you should go to bed after work. Enter your shift start time, the length of the shift, how long it takes to commute home, the minutes you need to unwind, and your target sleep duration to get a clock-specific sleep block.

Math

Circle Area

Compute the area enclosed by a circle using the formula A = πr².

Math

Circle Circumference Calculator

Compute the circumference of a circle from its radius.

Math

Circle Sector Area Calculator

Calculate the area of a circular sector from its radius and central angle.

Math

Circle Circumference from Area

Derive circumference when only area is known.

Other

Citation Density Calculator

Compute the number of citations per page to evaluate referencing density in legal briefs, academic papers, or policy reports.

Education & Learning

Class Attendance Percentage Calculator

Find the percentage of classes attended.

Education & Learning

Class Rank Percentile Calculator

Enter class rank (1 = top student) and total class size to compute percentile position.

Web & Marketing

Click-Through Rate Calculator

Determine the percentage of impressions that result in clicks for an ad or email campaign.

Web & Marketing

Click-To-Open Rate Calculator

Calculate the click-to-open rate (CTOR) by dividing unique clicks by unique opens and multiplying by 100.

Education & Learning

Clinical Hours Planner

Convert remaining practicum requirements into weekly patient-facing and simulation hours with absence buffers and lab credit ratios.

Technology & Coding

Clock Cycle Time Calculator

Convert clock frequency in megahertz to the duration of a single cycle in nanoseconds.

Technology & Coding

Cloud GPU Reservation Breakage Exposure

Estimate wasted spend from underutilized reserved GPU hours versus on-demand alternatives and resale credits.

Technology & Coding

Cloud Reserved Instance Savings Forecaster

Estimate whether committing to cloud reserved instances saves money versus staying on demand. Enter on-demand and reserved hourly rates, expected hours per month, utilisation, and the term length to see the absolute and percentage savings.

Technology & Coding

Cloud Savings Plan Coverage Calculator

Quantify how much of your eligible compute spend is protected by AWS or Azure savings plan commitments.

Technology & Coding

Cloud SIEM Log Ingestion Budget

Forecast monthly SIEM ingestion spend by pairing daily log volume with retention days, compression, and vendor pricing.

Technology & Coding

Cloud Storage Cost

Find the monthly bill for storing data in the cloud.

Conversions

Centimeters to Inches Converter

Convert a length from centimeters to inches.

Conversions & Units

CO₂ ppm ↔ mg/m³ Converter

Convert indoor CO₂ readings between parts per million and milligrams per cubic metre under custom temperature and pressure.

Math & Statistics

Coefficient of Variation Calculator

Calculate the coefficient of variation (CV) to compare variability across datasets.

Finance

Coffee Cost Savings Calculator

Estimate yearly savings from skipping your daily coffees.

Lifestyle & Travel

Coffee to Water Ratio

Calculate water needed for a coffee brew ratio.

Lifestyle & Travel

Coffee Water Ratio Calculator

Determine how much water to use for a given amount of coffee grounds and desired brew ratio.

Science & Engineering

Cold Chain Hold Time Calculator

Estimate how many hours temperature-sensitive payloads stay within range by combining thermal mass, allowable rise, and heat gain.

Technology & Coding

Color Contrast Checker

Enter RGB values for foreground and background colors to determine their contrast ratio.

Technology & Coding

Color Depth to Colors Calculator

Calculate how many distinct colors are possible for a given bit depth per pixel. Enter bits and press Calculate.

Math & Statistics

Combination Calculator

Compute n choose r combinations.

Science & Engineering

Comet Surface Brightness

Forecast coma surface brightness in mag/arcsec² using absolute magnitude, heliocentric and geocentric distances, and coma diameter.

Finance & Business

Commercial Loan DSCR Calculator

Check debt service coverage for a business loan and quantify the NOI gap to meet lender targets.

Other

Community Social Return on Investment Calculator

Translate program costs and monetised outcomes into a transparent social return on investment ratio with optional drop-off and horizon adjustments.

Home & DIY

Compost Carbon-Nitrogen Ratio

Determine the overall carbon-to-nitrogen ratio when mixing green and brown compost materials.

Finance

Compound Interest Growth Calculator

Forecast how a single lump-sum investment grows with compound interest by adjusting rate, compounding frequency, and years.

Technology & Coding

Compression Ratio Calculator

Compare original and compressed file sizes.

Technology & Coding

Compression Savings Calculator

See how much space you save after compressing files.

Home & DIY

Concrete Slab Volume

Volume for a slab in cubic meters.

Math & Statistics

Confidence Interval Calculator

Enter sample mean, standard deviation, sample size and confidence level to calculate the confidence interval around the mean.

Finance

Construction Cost per Square Foot

Find unit cost from total project cost and area.

Web & Marketing

Content Decay Recovery Forecast

Project the monthly traffic you can regain by refreshing decayed content using historical decline and expected recovery.

Productivity

Context Switching Cost Estimator

Put a dollar value on interruptions. Enter how many times you switch tasks per day, the minutes lost each switch, your fully loaded hourly rate, and working days per week to see the time and salary impact.

Finance

Contingency Fee Calculator

Estimate the lawyer's contingency fee from a settlement based on the agreed percentage.

Math & Statistics

Continued Fraction Approximation Tool

Find the best rational approximation of a real number using continued fractions within your chosen denominator limit.

Lifestyle & Travel

Convection Oven Time Converter

Adjust conventional recipe times for convection ovens.

Web & Marketing

Conversion Rate Calculator

Determine the percentage of visitors who complete a desired action such as a purchase or signup.

Web & Marketing

Conversion Uplift Impact Calculator

Model extra conversions, revenue, payback time, and ROI when a landing-page test improves conversion rate.

Web & Marketing

Core Web Vitals Conversion Impact

Translate faster LCP, INP, or CLS scores into conversion uplift, incremental revenue, and payback period.

Finance & Business

Corporate-Owned Life Insurance After-Tax Yield

Model the after-tax IRR, taxable-equivalent yield, and benefit multiple for a corporate-owned life insurance policy.

Web & Marketing

Cost Per Click Calculator

Calculate advertising cost per click.

Web & Marketing

Cost Per Lead Calculator

Measure how much you spend on average to acquire a single lead.

Web Marketing

Cost Per Thousand Impressions Calculator

Determine the cost per thousand impressions (CPM) by dividing total ad spend by impressions and multiplying by 1000.

Health & Fitness

CPAP Pressure Ramp Compliance Benefit

Check how ramp time, nightly use, and mask leak affect meeting the 4-hour CPAP compliance threshold.

Health & Fitness

CPAP Pressure Range & Mask Fit Budget Calculator

Estimate a comfort-focused auto-CPAP range and supply budget from your prescribed pressure, AHI, nightly usage, and mask cadence.

Technology

CPU Power to Current

Convert CPU power draw to current at given voltage.

Technology & Coding

CPU Utilization Calculator

Estimate CPU utilization percentage from measured busy time over total time.

Health & Fitness

Creatine Loading Planner

Plan creatine loading and maintenance grams based on body weight and schedule.

Personal Finance & Loans

Credit Card Minimum Payment Calculator

Estimate the minimum payment your credit card issuer will require.

Finance & Business

Credit Card Monthly Interest

Estimate monthly interest charges on a credit card balance.

Personal Finance & Loans

Credit Card Payoff Time Calculator

Estimate months to pay off a credit card balance.

Conversions & Units

Credit Hours to ECTS Converter

Translate academic credit hours into the European Credit Transfer and Accumulation System.

Finance & Business

Credit Utilization Ratio Calculator

Compute the percentage of your revolving credit limit currently in use to monitor credit score health.

Personal Finance & Loans

Credit Utilization Shock Planner

Project how limit cuts or big purchases change credit card utilization and the payment needed to recover targets.

Science & Engineering

Critical Damping Requirement

Compare actual damping with the critical coefficient for a single-degree-of-freedom system to avoid resonance.

Lifestyle & Travel

Cruise Drink Package Break-Even

Compare daily drink spending with the package price to see whether a cruise drink bundle pays off.

Science & Engineering

Cryogenic Tank Boil-Off Loss Analyzer

Convert boil-off percentages into daily mass loss, commodity cost, and vented emissions for cryogenic storage.

Finance

Crypto Mining Breakeven Time

Estimate days to recoup mining hardware cost.

Math

Cube Volume Calculator

Find the volume of a cube from its side length.

Education & Learning

CubeSat Orbit Planner

Estimate period, daily passes, ballistic coefficient, and atmospheric lifetime for a CubeSat given altitude, mass, and drag area.

Conversions & Units

Cups to Grams Flour Converter

Convert cups of all-purpose flour into precise gram weights so baking recipes stay consistent every time.

Conversions & Units

Cups to Tablespoons Converter

Convert volume in cups to tablespoons using the US customary system.

Finance

Currency Conversion Fee

See how much you receive after a conversion fee.

Home & DIY

Curtain Width Calculator

Determine total curtain width needed using a fullness ratio.

Web & Marketing

Customer Acquisition Cost Calculator

Determine cost per new customer from marketing spend.

Web & Marketing

Customer Retention Rate Calculator

Enter number of customers at the start and end of a period plus new customers acquired to calculate retention rate.

Technology & Coding

Cyber Insurance Coverage Gap Analyzer

Quantify cyber loss exposure left after limits, retention, exclusions, and incident probability assumptions.

Education & Learning

Cybersecurity Certification ROI Calculator

Project multi-year ROI for cybersecurity certifications by blending salary uplift, pass odds, and ongoing maintenance costs.

Math

Cylinder Volume Calculator

Calculate the volume of a cylinder from radius and height.

Health

Daily Calorie Burn (Rough)

Estimate daily calories burned from your step count and exercise time.

Health & Fitness

Daily Fiber Requirement Calculator

Estimate daily fiber needs based on calorie intake.

Personal Finance & Loans

Daily Micro-Savings Growth Calculator

See how small daily deposits, skipped days, and starting balances grow with daily compounding over a custom timeline.

Health & Fitness

Daily Protein Intake Calculator

Estimate an individualized daily protein target based on body weight and activity level.

Health

Daily Protein Needs Calculator

Estimate daily protein requirement from body weight.

Lifestyle & Travel

Daily Travel Budget Calculator

Divide total trip budget by days to plan daily spending.

Health

Daily Water Intake Calculator

Rough estimate of daily water intake from body weight.

Science & Engineering

Data Center Free Cooling Hours Calculator

Estimate annual free cooling availability from supply temperature, economizer approach, weather bins, and operational allowances.

Science & Engineering

Data Center Heat Reuse Payback Calculator

Estimate heat revenue, recovered MMBtu, avoided emissions, and simple payback for a data center heat-reuse retrofit.

Science & Engineering

Data Center PUE Improvement ROI Calculator

Estimate energy savings, cost reduction, and payback from improving data center PUE toward a target.

Technology

Data Center PUE Calculator

Calculate Power Usage Effectiveness for a data center.

Technology

Data Center Water Usage Effectiveness (WUE) Calculator

Benchmark cooling water stewardship by dividing annual make-up water consumption by IT energy output.

Technology & Coding

Data Transfer Cost Calculator

Calculate the monetary cost of transferring data based on usage and per-gigabyte pricing.

Technology

Data Transfer Time Calculator

Estimate how long it will take to transfer a file over a network connection using its size in megabytes and your available bandwidth.

Technology & Coding

Data Warehouse Query Cost Allocation

Allocate cloud data warehouse charges down to an individual query using runtime, credit pricing, concurrency, and data services fees.

Technology & Coding

Database Connection Pool Size Planner

Estimate the number of database connections required by combining steady-state throughput, burst multipliers, and headroom.

Technology & Coding

Database Growth Projection

Estimate months until a database reaches capacity.

Date & Time

Day of the Week Finder

Determine the weekday for any date.

date-time

Day of Year Calculator

Determine the day number within the year for a given date, accounting for leap years.

Date & Time

Daylight Duration

Find total daylight hours from sunrise and sunset times.

Date & Time

Daylight Saving Countdown

Enter a date and region to see how many days remain until the next daylight saving time change.

Date & Time

Days Between Dates Calculator

Count the number of days between two dates.

Date & Time

Days in Month Calculator

Return the number of days in a specific month and year, accounting for leap years.

Date & Time

Days to Hours Calculator

Quickly convert any number of days into equivalent hours.

Date & Time

Days to Seconds Converter

Convert a duration in days to total seconds. Enter the value and press Calculate.

Date & Time

Days to Weeks Converter

Convert days into weeks (may be fractional).

Personal Finance & Loans

Debt Avalanche vs Snowball Comparison

Enter your total monthly payoff budget and up to three debts to compare how much interest the avalanche method can save versus the snowball approach.

Finance

Debt Payoff Time Calculator

Estimate months needed to pay off a debt with fixed monthly payments.

Finance & Business

Debt Service Coverage Ratio Calculator

Compute the DSCR by dividing net operating income by total debt service. Values above 1 indicate adequate income to cover debt obligations.

Personal Finance & Loans

Debt-to-Asset Ratio Calculator

Find the percentage of assets financed by debt by dividing total liabilities by total assets and multiplying by 100.

Finance & Business

Debt-to-Equity Ratio Calculator

Assess a company's leverage by comparing liabilities to equity.

Finance & Business

Debt-to-Income Ratio Calculator

Compute your debt-to-income (DTI) ratio as a percentage using monthly debt payments and gross monthly income.

Conversions & Units

Decibel to Power Percentage Calculator

This tool converts a decibel (dB) value into a corresponding power percentage relative to the reference level. Enter a dB value to see the equivalent percent of power.

Conversions & Units

Decimal to Percentage Converter

Convert decimals to percentages for reports and presentations.

Home & DIY

Deck Board Quantity Calculator

Estimate number of decking boards needed for a project.

Home & DIY

Decorative Concrete Curing Schedule

Estimate when stamped or polished concrete is ready for foot traffic, heavy work, sealing, and service.

Science & Engineering

Deep-Sky Exposure Planner

Derive optimal sub-exposure times, light frames, and calibration counts by balancing target signal, sky glow, and read noise.

Personal Finance & Loans

Deferred Compensation Bridge Planner

Project how long deferred compensation installments can cover lifestyle spending before income resumes.

Home & DIY

Desk Cable Length

Cable length needed from desk to outlet.

Lifestyle & Travel

Destination Wedding Total Cost Forecaster

Roll travel stipends, venue packages, and vendor extras into a per-guest budget, payment plan, and monthly savings target for a destination wedding.

Math & Statistics

3x3 Determinant Calculator

Evaluate the determinant of any 3×3 matrix to test invertibility, compute cross products, or solve linear systems.

Science & Engineering

Dew Point Calculator

Estimate the dew point temperature from ambient air temperature and relative humidity using the Magnus formula.

Lifestyle & Travel

Dice Roll Probability Calculator

Find the probability of rolling a specific value at least once with multiple dice. Enter sides and number of dice, then press Calculate.

Health & Fitness

Diet Macro Calculator

Specify total daily calories, macro percentage, and calories per gram to find grams for a given macro nutrient.

Lifestyle & Travel

Digital Nomad Visa Budget Planner

Check whether your monthly income clears digital nomad visa rules after rent, lifestyle costs, dependents, insurance, and a currency buffer.

Science & Engineering

Direct Air Capture Credit Stack Planner

Blend 45Q credits with voluntary offtake prices to measure net revenue per ton and payback for direct air capture projects.

Science & Engineering

Direct Air Capture LCO₂ Calculator

Blend energy, capital recovery, sorbent makeup, and credits to estimate the net levelized cost per tonne of CO₂ removed.

Science & Engineering

Direct Air Capture Sorbent Productivity Calculator

Evaluate annual CO₂ captured per tonne of active sorbent using capture rate, sorbent inventory, uptime, and capture efficiency.

Science & Engineering

Direct Lithium Extraction Yield Calculator

Convert brine volume, lithium concentration, and recovery rate into annual LCE tonnage and gross revenue.

Math & Statistics

Direct Proportion Rule of Three Calculator

Solve a direct rule-of-three proportion by entering the three known quantities.

other

Discount Calculator

Compute the sale price after applying a percentage discount.

Lifestyle & Travel

Distance to Horizon Calculator

Enter the observer's height to approximate the distance to the horizon using Earth's curvature.

Finance & Business

Dividend Payout Ratio

Determine what percentage of earnings is distributed to shareholders as dividends.

Finance & Business

Dividend Reinvestment Calculator

Estimate the future value of an investment when dividends are reinvested and the stock price grows annually. Enter initial investment, dividend yield, growth rate, and years.

Finance & Business

Dividend Yield Calculator

Estimate dividend yield from dividend and share price.

Other

Dog Age in Human Years

Convert a dog's age to an equivalent human age.

Science & Engineering

Doppler Effect Frequency Shift Calculator

Enter the source frequency, velocities and speed of sound to compute the observed frequency using the Doppler effect.

Personal Finance & Loans

Down Payment Calculator

Calculate the upfront amount needed for a purchase based on price and down payment percentage.

Technology

Download Cost Calculator

Estimate the price of downloading data based on file size and cost per gigabyte.

Technology

Download Time

Estimate how long a file download will take based on size and speed.

Technology

DPI Calculator

Dots per inch from pixels and inches.

Home & DIY

Drain Pipe Slope Calculator

Calculate the slope needed for proper drainage in plumbing or landscaping.

Home & DIY

Drip Irrigation Water Usage

Estimate weekly water applied by a drip irrigation zone from emitter count, flow rate, runtime, and watering frequency.

Technology & Coding

Drone Flight Time Calculator

Estimate multirotor flight endurance using battery capacity, current draw, and payload weight. Plan missions with realistic hover time and reserve margins before launch.

Home & DIY

Drywall Sheet Quantity Calculator

Estimate the number of drywall sheets needed from total wall area and sheet dimensions.

Home & DIY

Drywall Sheets Calculator

Estimate the number of drywall sheets needed.

Home & DIY

Drywall Weight Calculator

Estimate drywall weight from coverage area and panel thickness to plan safe handling, delivery, and structural loads.

Finance & Business

DSCR Loan Covenant Cushion Calculator

Measure DSCR, NOI headroom, and stress-test declines to see how close you are to breaching a commercial loan covenant.

date & time

Duration to Seconds

Convert hours, minutes, and seconds into a single total in seconds.

Personal Finance & Loans

Early 401(k) Hardship Withdrawal Impact

Estimate penalties, taxes, and net cash from an early 401(k) hardship withdrawal before tapping retirement funds.

Finance & Business

Earnings Per Share Calculator

Determine a company's earnings per share by subtracting preferred dividends from net income and dividing by shares outstanding.

Date & Time

Earth Years to Mars Years

Convert the time span of Earth years into their equivalent length in Mars years.

Other

Earthquake Energy Release Calculator

Convert earthquake magnitude to energy in joules.

Finance & Business

EBITDA Margin Calculator

Calculate EBITDA margin from revenue, operating costs, and non-cash expenses.

Finance & Business

E-commerce Break-even Calculator

Determine how many units you must sell to break even after manufacturing, shipping, advertising and platform fees.

Finance & Business

E-commerce EOQ with Volume Discount

Blend EOQ theory with supplier quantity breaks so you can decide whether a bulk buy truly lowers total cost. Input your demand, carrying costs, and discount tier to instantly compare scenarios.

Education & Learning

ECTS Weekly Workload Calculator

Convert European Credit Transfer System (ECTS) credits into weekly study hours with contact vs self-study splits.

Technology & Coding

Edge Data Center Space Planner

Size micro or edge data centers by combining rack footprints, aisle spacing, and power headroom. Quickly estimate how much white space you need before signing leases or ordering prefabricated enclosures.

Technology & Coding

Edge Inference Latency Budget Planner

Allocate an end-to-end SLA across capture, networking, inference, and post-processing to reveal the milliseconds available for your model.

Web & Marketing

EEAT Cluster Coverage Score

Score topic clusters on Expertise, Experience, Authority, and Trust (EEAT) by combining publication coverage, expert bylines, citations, and fresh updates.

Home & DIY

Electricity Cost per Month

Estimate monthly electricity cost of an appliance.

Science & Engineering

Electrolyzer Capacity Factor Calculator

Quantify electrolyzer capacity factor by reconciling metered energy with nameplate power over a defined period.

Science & Engineering

Electrolyzer Specific Energy Consumption Calculator

Determine kWh per kilogram of hydrogen by combining power draw, runtime, and production output.

Science & Engineering

Electrolyzer Water Demand Planner

Dimension the makeup water, recycle needs, and cost for a hydrogen electrolyzer project.

Conversions & Units

Electronvolt to Joule Converter

Convert electronvolts (eV) to joules (J) with CODATA 2018 precision. Enter subatomic or high-energy physics values and receive a properly formatted SI result for lab reports, spectroscopy, or semiconductor work.

Math

Ellipse Area Calculator

Find the area of an ellipse from its semi-major and semi-minor axes.

Web & Marketing

Email List Growth Rate Calculator

Calculate the average monthly growth rate of your email list by comparing starting and ending subscribers over a period.

Web & Marketing

Email Open Rate Calculator

Calculate the percentage of delivered emails that registered an open event. Use the result to benchmark campaigns, monitor list health, and refine subject lines.

Web & Marketing

Email Send Saturation Calculator

Balance send frequency with fatigue by estimating the monthly cadence that preserves opens while respecting unsubscribe limits.

Technology & Coding

Embedded Lending API Cost Planner

Project the fully loaded cost per funded loan by combining decisioning fees, approval rates, revenue share, and credit reserves.

Finance

Emergency Fund Duration

Estimate how many months your savings can cover expenses.

Finance

Emergency Fund Runway Planner

Estimate how many months your emergency savings can cover once you factor in partial income and one-time cash buffers.

Personal Finance & Loans

Emergency Fund Target

Find the recommended emergency fund size based on monthly expenses and months of coverage.

Home & DIY

Emergency Roof Replacement Cash-Flow Planner

See the cash shortfall after insurance, savings, and deductibles plus financing payments for emergency roof work.

Finance & Business

Employee Cost per Hour Calculator

Calculate the hourly cost of an employee by factoring salary, benefits, and overhead and dividing by annual work hours.

Finance & Business

Employee Retention Credit Repayment Reserve Calculator

Size an ERC repayment reserve by combining the at-risk claim, potential penalties, and IRS interest accrual.

Other

Employee Turnover Rate

Calculate staff turnover percentage over a period.

Nutrition

Endurance Electrolyte Replacement Calculator

Dial in sodium, potassium, and magnesium targets for long endurance sessions. Enter your sweat rate, lab-tested or estimated mineral losses per litre, and planned duration to see hourly and total replacement goals.

Technology

Energy Reuse Effectiveness (ERE) Calculator

Quantify data center energy reuse effectiveness by comparing net facility energy to IT energy delivery.

Home & DIY

Energy Star Window Payback Calculator

Estimate the payback period for Energy Star window upgrades after rebates, U-factor improvements, and energy savings.

Science & Engineering

Building Energy Use Intensity (EUI) Calculator

Benchmark a facility by converting annual energy consumption into site EUI in kBtu/ft²·yr and the equivalent metric intensity.

Finance & Business

Enterprise Value Sensitivity to WACC Calculator

Model how shifts in your weighted average cost of capital compress or expand enterprise and equity value.

Technology & Coding

Error Budget Burn Rate Calculator

See how quickly your team is consuming the error budget by comparing observed downtime to the allowance implied by your availability SLO.

Science & Engineering

Escape Velocity Calculator

Calculate the speed required to break free from a planet or moon's gravity.

Education & Learning

Essay Word Goal Calculator

Determine how many words you still need to write to meet your assignment requirement.

Finance & Business

EU Carbon Border Adjustment Duty Estimator

Calculate annual and quarterly CBAM certificate costs from imported tonnage, carbon intensity, and free allocations.

Finance & Business

EU CBAM Liability Calculator

Estimate certificate obligations and costs under the EU Carbon Border Adjustment Mechanism.

Lifestyle & Travel

EU261 Flight Compensation

Check the flat-rate payment you could claim when an EU or UK carrier arrives late. Provide the great-circle distance of the disrupted itinerary and the total hours delayed on arrival; the calculator applies the official EU261/UK261 brackets to reveal the headline compensation amount.

Science & Engineering

EV Battery Recycling Revenue Margin Calculator

Calculate gross margin from processing spent EV batteries using recovery yield, commodity pricing, and processing costs.

Science & Engineering

EV Charger Diversity Factor Calculator

Translate charger nameplate sums and observed coincident peaks into a diversity factor for fleet charging depots.

Conversions & Units

EV Charging Rate Unit Converter

Convert charger power into miles of range gained per hour and estimate session time across a state-of-charge window.

Lifestyle & Travel

EV Cost per Kilometer Calculator

Enter energy consumption per 100 km and electricity cost to estimate driving cost per kilometer.

Home & DIY

EV Panel Upgrade Payback Estimator

Compare panel upgrade costs with off-peak charging savings and incentives to find breakeven timing.

Finance & Business

EV Total Cost of Ownership with Battery Degradation

Project the multi-year spend for an electric vehicle by combining charging costs, maintenance, and the value lost as the battery degrades. Ideal for comparing EVs to ICE vehicles or planning fleet budgets.

Personal Finance & Loans

EV vs. Gas Total Cost of Ownership

Compare multi-year ownership cost for an electric vehicle versus a gasoline car using purchase, energy, and upkeep inputs.

Math

Evidence Percentage Calculator

Find percentage of evidence weight vs total.

Science & Engineering

Exoplanet Transit SNR Calculator

Model transit detectability by combining host-star size, planet radius, detector noise, and stacked exposures to return an SNR score.

Health

Eye Break Time

Apply the 20-20-20 rule to long screen sessions and see how much recovery time you should schedule for healthier eyes.

Conversions

Fahrenheit to Celsius Converter

Convert Fahrenheit temperatures to Celsius.

Math & Statistics

Factorial Calculator

Multiply all positive integers up to n to find n factorial.

Conversions & Units

Fahrenheit to Kelvin Converter

Convert temperature from Fahrenheit to Kelvin.

Technology & Coding

Feature Flag Rollout Impact Calculator

Estimate how a feature flag rollout consumes error budget based on traffic and defect rates.

Web & Marketing

Featured Snippet Opportunity Calculator

Estimate the incremental monthly visits you could gain by capturing a featured snippet for a keyword you already rank for.

Conversions & Units

Feet per Second to Miles per Hour

Convert speed in feet per second to miles per hour. Enter ft/s and press Calculate.

Health & Fitness

Female Athlete Iron Deficit Estimator

Estimate storage and hemoglobin iron deficits for female athletes using ferritin, hemoglobin, body weight, and training load context.

Home & DIY

Fence Paint Quantity Calculator

Estimate how many litres of paint are required to cover a fence based on dimensions and product coverage.

Home & DIY

Fence Post Concrete Calculator

Estimate concrete volume for fence posts.

Home & DIY

Fence Post Count

Estimate number of posts needed for a straight fence.

Home & DIY

Fence Post Spacing

Determine how many fence posts you need for a straight fence based on total length and spacing between posts.

Health

Fertility Treatment Net Cost Planner

Estimate out-of-pocket and financed costs for IVF or IUI after insurance coverage caps, medication, and lender terms.

Math & Statistics

Fibonacci Number Calculator

Compute any Fibonacci number using Binet's formula by specifying its position in the sequence.

Technology

3D Printer Filament Volume Calculator

Convert filament length and diameter into material volume to plan 3D printing projects and material costs.

Education & Learning

Final Exam Score Needed

Calculate the minimum final exam score needed to achieve a desired course grade.

Finance

Final Price Calculator

Apply a generic percent change.

Finance

FIRE Number Calculator

Compute target savings for financial independence using annual expenses and withdrawal rate.

Finance & Business

FIRE Timeline Calculator

Estimate how many years it will take to reach financial independence based on current savings, annual contributions, investment return and inflation.

Education & Learning

Flashcard Interval Calculator

Use this calculator to estimate the next review interval in a spaced repetition system. Multiply the previous interval by an ease factor to plan your study schedule.

Education & Learning

Flashcard Retention Rate Calculator

Determine your flashcard retention rate by dividing recalled cards by total cards and converting to a percentage.

Education & Learning

Flesch-Kincaid Readability Calculator

Analyze sentences, words, and syllables to find the Flesch–Kincaid grade level of any text.

Lifestyle & Travel

Flight Carbon Footprint

Estimate the carbon dioxide emissions generated by a flight based on distance traveled.

Health & Fitness

Flight Water Intake

Estimate the total amount of water you should plan to drink during a flight based on travel time and your personal hydration goal per hour.

Home & DIY

Floor Tile Quantity

Tiles needed to cover a rectangular floor.

Home & DIY

Flooring Cost Calculator

Estimate material costs for new flooring based on room size and price per square meter.

Science & Engineering

Force from Mass and Acceleration

Apply Newton's second law to calculate force from mass and acceleration. Provide values for both to see the resulting force in newtons.

Finance & Business

Foreign Tip Converter

Convert a tip into your home currency.

Math

Fraction to Decimal

Convert a fraction to decimal form.

Lifestyle & Travel

Fractional Jet Share True Cost Calculator

Reveal the all-in hourly cost of a fractional jet share by blending buy-in amortization, management dues, hourly rates, and residual value assumptions.

Technology

Frame Time from FPS

Get milliseconds per frame from frames per second.

Finance & Business

Freelance Minimum Rate Calculator

Blend desired take-home pay, taxes, expenses, and downtime to find the minimum billable hourly rate you need.

Finance

Freelancer Hourly Rate

Find required hourly rate from income goals.

Finance

Freelancer Quarterly Tax Cushion

Work out the monthly reserve needed to cover quarterly income tax, VAT, and social contributions after accounting for deductions and withholdings.

Health & Fitness

Functional Threshold Power Progression Planner

Project how a training block could lift your cycling FTP by combining planned weekly watt gains with an adherence multiplier.

Lifestyle & Travel

Fuel Cost Per Mile Calculator

Calculate cost per mile from fuel price and mileage.

Finance

Fuel Trip Cost Calculator

Estimate the fuel expense for a road trip using distance, consumption, and fuel price.

Date & Time

Fulfillment SLA Capacity Planner

Project same-day shipping cutoffs, backlog, and overtime needed to hit e-commerce fulfillment SLAs.

Web & Marketing

Marketing Funnel Drop-off Calculator

Enter lead counts at each stage to calculate percentage drop-off and final conversion.

Conversions

Furlongs per Fortnight to Meters per Second

Convert the whimsical speed unit of furlongs per fortnight into meters per second.

Finance

Future Value of Annuity (End)

Future value of equal monthly deposits.

Conversions & Units

Gallons to Liters Converter

Convert US gallons to liters.

Home & DIY

Garage Epoxy Coverage Calculator

Plan how many gallons of epoxy coating you need for a garage floor based on square footage and product coverage.

Home & DIY

Garage Ramp Slope Calculator

Find ramp slope percentage from rise and run.

Home & DIY

Garden Soil Volume

Compute soil volume for a rectangular bed (m³).

Home & DIY

Garden Soil Weight

Estimate total soil weight for a rectangular garden bed using dimensions and soil density.

Math & Statistics

Greatest Common Divisor (GCD) Calculator

Compute the greatest common divisor of two numbers using the Euclidean algorithm.

Technology

Gear Ratio Calculator

Calculate gear ratio from tooth counts.

Technology & Coding

GenAI P95 Latency Budget Calculator

Project the 95th percentile latency for a generative AI prompt pipeline using log-normal assumptions and additive overheads.

Technology & Coding

GenAI QA Budget Planner

Forecast monthly quality assurance spend for generative AI releases across tokens, human review, and monitoring.

Technology & Coding

Generative AI API Rate Card Profitability Checker

Check generative AI API unit economics, from cost per request to margin targets and breakeven token pricing.

Technology & Coding

Generative AI API Rate-Limit Budget Calculator

Translate daily active users into sustained rate limits, token throughput, and projected monthly spend for hosted LLM APIs, complete with budget variance checks.

Technology & Coding

Generative AI Inference Unit Cost Calculator

Translate token pricing and usage into per-request cost, cost per million calls, and breakeven subscription pricing.

Math

Geometric Mean (2 Numbers)

Compute the geometric mean of two values.

Math

Geometric Series Sum

Sum of the first n terms of a geometric series.

Home & DIY

Geothermal Heat Pump ROI Evaluator

Size a residential geothermal system, estimate installed cost after incentives, and project annual energy savings.

Home & DIY

Geothermal Heat Pump Payback

Work out how quickly a ground-source heat pump can repay itself. Enter the turnkey installation price, all rebates or tax credits, and the annual savings you expect from lower utility bills plus reduced maintenance to see the breakeven timeline in years.

Date & Time

Global Work Hours Overlap Finder

Calculate the shared working-hour window across two or three time zones after converting schedules into UTC hours.

Health & Fitness

GLP-1 Therapy Annual Out-of-Pocket Planner

Project yearly GLP-1 medication costs after insurance coverage, copay support, and optional monthly add-ons.

Health & Fitness

GLP-1 Therapy Insurance Cost Estimator

Estimate GLP-1 medication out-of-pocket costs after deductibles, coinsurance, copay cards, and pharmacy fees.

Health & Fitness

GLP-1 Therapy Out-of-Pocket Cost Calculator

Estimate monthly and total GLP-1 medication costs after insurance coverage and savings-card support, and see exactly when assistance caps are exhausted.

Health & Fitness

GLP-1 Treatment Monthly Budget Forecaster

Blend insurance coverage, copay cards, and clinic fees to project the monthly out-of-pocket cost of GLP-1 therapy.

Nutrition

Glycemic Load Calculator

Multiply the carbohydrate content of a serving by its glycemic index and divide by 100 to get glycemic load.

Math

Golden Ratio Calculator

Compute the longer side of a rectangle using the golden ratio.

Web & Marketing

Google Ads ROAS vs LTV Payback Calculator

Project revenue, ROAS, CAC, and payback timeline for a Google Ads campaign using order value, conversion rate, and retention.

Web & Marketing

Google Ads Target CPA Breakeven Calculator

Check whether a proposed target CPA maintains profit after margin, LTV multipliers, extra costs, and conversion rate.

Education & Learning

GPA Calculator

Compute your grade point average by dividing total quality points by total credits attempted.

Education & Learning

GPA to UCAS & IB Converter

Translate domestic grades into international thresholds in seconds. Provide your GPA and the maximum value on your transcript to normalise the score and estimate comparable UCAS Tariff points plus an IB Diploma total for application planning.

Conversions & Units

GPM to LPS Converter

Quickly convert flow rates from US gallons per minute to liters per second—handy for plumbing and irrigation setups.

Technology & Coding

GPU Inference Cost per 1K Requests Calculator

Translate GPU hourly pricing, throughput, and request volume into cost per 1,000 requests and monthly spend.

Technology & Coding

GPU Spot vs On-Demand Breakeven

Compare spot and on-demand GPU pricing, including interruption overhead, to see when savings disappear.

Math

Grade Average

Compute the average from three test scores.

Conversions

Grams to Ounces Converter

Convert grams to ounces quickly.

Lifestyle & Travel

Grant Application Success Probability

Calculate the probability of at least one successful grant when submitting multiple applications.

Home & DIY

Grass Seed Coverage Calculator

Determine the amount of grass seed required by dividing lawn area by the coverage rate provided on the seed bag.

Science & Engineering

Gravitational Potential Energy Calculator

Calculate gravitational potential energy by multiplying mass, gravitational acceleration, and height.

Conversions & Units

Greenhouse Gas Unit Converter

Translate greenhouse gas mass into CO₂-equivalent and electricity usage using global warming potential factors.

Home & DIY

Greywater Irrigation Sizing Calculator

Balance greywater supply, irrigation demand, and storage needs to plan compliant reuse systems for landscapes.

Science & Engineering

Grid Interconnection Delay Carry Cost Calculator

Quantify burn and financing drag while renewable projects wait in interconnection queues.

Finance & Business

Gross Margin Calculator

Determine gross margin percentage from revenue and cost of goods sold. Enter the values and press Calculate.

Finance & Business

Gross Profit Margin Calculator

Calculate gross profit margin percentage from revenue and cost of goods sold.

Finance & Business

Gross Revenue Retention Calculator

Quantify how much recurring revenue remains after downgrades and churn so you can benchmark cohort durability.

Finance & Business

Gross-Up Calculator

Determine the pre-tax amount required to provide a specific net payment.

Education & Learning

Group Project Contribution Split Planner

Build a fair workload split for team assignments. Enter total project hours, the number of teammates, a buffer percentage, and the share of work to reassign if one member falls behind to see per-person allocations.

Math

Harmonic Mean (3 Numbers)

Compute the harmonic mean of three values.

Math & Statistics

Harmonic Mean Calculator

Find the harmonic mean of three positive numbers, useful for averaging rates.

Technology & Coding

Hash Collision Probability Calculator

Estimate hash collision risk with the birthday paradox using hash count and bit length inputs.

Technology & Coding

Hashrate Efficiency Calculator

Compute mining hashrate per watt of power.

Health & Fitness

HDHP vs PPO Out-of-Pocket Crossover

Compare annual costs, employer HSA offsets, and the claim level where a PPO becomes cheaper than a high-deductible health plan.

Health

Division Calculator

Divide one number by another to find the quotient.

Health

Healthy Waist Limit

Estimate a healthy maximum waist circumference as half your height.

Health

Heart Rate Reserve Percentage

Current training intensity as a percentage of heart rate reserve.

Science & Engineering

Heat Exchanger NTU-Effectiveness Calculator

Compute NTU and thermal effectiveness for a counterflow heat exchanger using capacity rates and UA.

Health

Heat Index Calculator

Estimate perceived temperature from air temperature and humidity.

Science & Engineering

Heat Pump Balance Point Calculator

Solve for the outdoor temperature where a heat pump's capacity equals the building heat loss.

Home & DIY

Heat Pump vs Gas Furnace Cost Breakeven

Estimate the seasonal operating cost difference between a heat pump and a gas furnace. Enter your annual heating load, heat pump COP, electricity rate, furnace AFUE, and local gas price to see which system is cheaper and by how much.

Science & Engineering

Heat Pump Seasonal Performance Factor Calculator

Quantify a heat pump's seasonal performance factor (SPF) by combining delivered heat and all electrical inputs, including optional backup resistance heat and auxiliary pumps.

Home & DIY

Heat Pump vs Gas Furnace Annual Cost Comparator

Compare yearly operating cost and emissions for a heat pump versus a gas furnace using load, COP, and utility rates.

Home & DIY

Heat Pump vs Gas Furnace Bill Crossover Calculator

Compare annual operating costs and emissions for a heat pump versus a gas furnace and find the gas price breakeven.

Home & DIY

Heat Pump Water Heater Incentive Stack

Stack federal credits with state and utility rebates to reveal your net heat pump water heater cost and payback timeline.

Conversions & Units

Hectares to Acres Converter

Convert farm, forestry, and surveying land measurements from hectares to acres with survey-grade precision.

Personal Finance & Loans

HELOC Draw & Repayment Planner

Estimate the total amount you will pay on a home equity line of credit (HELOC) by combining the interest-only draw period with the fully amortising repayment period. Enter the amount you plan to draw, the annual interest rate, and the lengths of both phases to forecast cumulative payments.

Personal Finance & Loans

HELOC Recast Break-Even Analyzer

Compare HELOC interest-only costs, recast payments, and a refinance option to see when closing costs pay for themselves.

Personal Finance & Loans

HELOC Reset Payment Shock Calculator

Forecast how much a HELOC payment jumps when the draw period ends, compare it to your target budget, and solve for the refinance rate that would keep payments in line.

Personal Finance & Loans

HELOC vs Cash-Out Refinance Breakeven Calculator

Compare HELOC-plus-mortgage payments against a full cash-out refi to see monthly savings, breakeven timing, and lifetime interest impact.

Technology & Coding

Hex to Decimal Converter

Instantly convert hexadecimal numbers (base 16) to their decimal (base 10) equivalents.

Math & Statistics

Regular Hexagon Area Calculator

Find the area of a regular hexagon using the standard formula based on side length. Enter the side length and press Calculate.

Web & Marketing

High-Intent Keyword Bid Ceiling Calculator

Calculate the break-even CPC for a high-intent keyword, derive a safe bid range, and size revenue potential from impression forecasts while respecting ROAS and margin goals.

Math & Statistics

Hiking Elevation Gradient

Compute slope percentage of a hike.

Lifestyle & Travel

Hiking Time Estimator

Plan hiking itineraries with Naismith's rule using distance and elevation gain.

Conversions

Hogsheads to Liters

Convert traditional hogshead cask volumes to liters.

Home & DIY

Division Calculator

Divide one number by another to find the quotient.

Personal Finance & Loans

Home Equity vs Cash-Out Breakeven Planner

Compare HELOC interest-only costs with a cash-out refinance to see how long it takes monthly savings to repay closing costs.

Home & DIY

Home EV Charger Demand Charge Avoidance

Estimate monthly demand-charge savings from shifting EV charging into off-peak windows with a time-of-use plan.

Home & DIY

Home Generator Sizing Calculator

Determine the recommended size of a standby generator by combining your running load, the largest startup surge, and a safety margin. Enter wattages for essential circuits and choose a buffer percentage.

Environment

Home Insulation Carbon Payback Calculator

See how long insulation upgrades take to pay back their embodied carbon. Enter the embodied carbon per square metre, the area being insulated, expected annual emissions avoided, and an efficiency realisation factor to estimate the payback period in years.

Home & DIY

Home Solar Profitability Forecaster

Project net savings, payback period, and ROI for a residential solar array with optional export credits and degradation.

Home & DIY

Home Standby Generator Fuel Burn & Runtime

Estimate runtime and fuel spend for a standby generator using load, tank size, hourly burn, and fuel price.

Home & DIY

Home Studio Acoustic Dampening Planner

Estimate how much acoustic treatment your room needs to hit a target decibel reduction based on room geometry and existing absorption.

Home & DIY

Home Warranty Deductible Breakeven Calculator

Compare warranty premiums, deductibles, and denial risk with expected repairs to find breakeven claim volume and net savings.

Lifestyle & Travel

Horse Age in Human Years

Translate your horse's age into an estimated human equivalent with a refined equine life stage guide, plus care tips by age.

Conversions

Horsepower to Watts Converter

Convert mechanical horsepower to watts.

Lifestyle & Travel

Hotel Elite Status Budget Calculator

Project the extra cash needed to unlock hotel elite status via nights and spend requirements.

Lifestyle & Travel

Hotel Nights Within Budget

See how many hotel nights your budget can cover.

Lifestyle & Travel

Hotel Point Value Calculator

Evaluate how much each hotel loyalty point is worth by dividing the cash price of a stay by the number of points required.

Lifestyle & Travel

Hotel Points to Nights Calculator

Estimate how many free nights you can redeem by dividing your total points by points required per night.

Finance & Business

Hotel Stay Cost

Estimate total hotel cost including taxes.

Lifestyle & Travel

Hotel vs Airbnb Total Cost Calculator

Compare full-stay costs between hotels and short-term rentals by including taxes, cleaning fees, and optional parking or resort charges.

Finance & Business

Hourly to Annual Salary

Convert an hourly wage into an annual salary for budgeting.

Date & Time

Hours to Minutes Converter

Convert hours to minutes.

Date & Time

Hours to Seconds Converter

Convert hours into total seconds.

Science & Engineering

Household Water Footprint Calculator

Estimate annual direct and indirect water use for your household, factoring optional reuse savings.

Health & Fitness

HRV & Sleep Readiness Score

Blend today’s HRV, sleep duration, perceived sleep quality, and acute training load to decide how hard to train.

Health & Fitness

HSA Contribution Tax Savings Estimator

Quantify federal and state tax savings from health savings account contributions and the effective after-tax cost.

Personal Finance & Loans

100 Envelope Challenge Savings Tracker

Forecast how much cash you will stack from the 100-envelope challenge by defining the envelope values, draw frequency, and optional top-up.

Conversions & Units

Hybrid Event Emissions Calculator

Blend in-person travel, on-site services, swag, and livestreaming activity to estimate the total CO₂e footprint of a hybrid event.

Technology & Coding

Hybrid Team Burnout Risk Calculator

Quantify burnout risk for hybrid teams by combining workload, meeting load, on-call rotations, time off, and pulse survey sentiment.

Science & Engineering

Hydrogen Backup Storage Sizing Calculator

Calculate the hydrogen mass required to cover critical loads during outages with efficiency losses and safety buffers.

Science & Engineering

Hydrogen Electrolyzer 45V Tax Credit Optimizer

Map clean hydrogen production, lifecycle carbon intensity, and incremental clean power costs to the Section 45V credit tier.

Science & Engineering

Hydrostatic Pressure Calculator

Determine the pressure exerted by a static fluid at a given depth using ρ g h.

Science & Engineering

Hyperscaler Savings Plan Buyout Evaluator

Compare the present value of remaining cloud savings plan commitments against a negotiated buyout discount.

Personal Finance & Loans

I Bond Rate Calculator

Combine the fixed rate and semiannual inflation rate to estimate the current U.S. Series I Bond composite yield.

Health

Ideal Body Weight (Devine)

Estimate ideal body weight using the Devine formula.

Health & Fitness

Ideal Body Weight Calculator

Estimate ideal body weight with the Devine formula using height in inches and a gender-specific base value.

Science & Engineering

Ideal Gas Pressure Calculator

Estimate pressure using the ideal gas law.

Personal Finance & Loans

Income-Driven Repayment vs. Refinance Analyzer

Compare estimated IDR payments with a refinance quote to see which option frees up more monthly cash flow.

Technology & Coding

Image File Size Calculator

Estimate uncompressed bitmap file size from image dimensions and bit depth before exporting graphics.

Finance & Business

Import Currency Hedge Coverage

Compare the landed local-currency cost of settling a supplier invoice immediately at the spot exchange rate versus locking in a forward contract. Enter the foreign currency amount, the quoted spot and forward rates, and any bank markups or transaction fees that differ between the two paths to understand the net hedge impact.

Personal Finance & Loans

Incentive Stock Option AMT Cushion Forecaster

Project the alternative minimum tax hit from an ISO exercise and confirm whether your cash reserve covers the exposure.

Conversions & Units

Inches to Centimeters Converter

Convert a length in inches to centimeters. Enter the value and press Calculate.

Personal Finance & Loans

Income-Driven Repayment Tax Bomb Reserve Planner

Forecast tax on forgiven student loans and map the monthly savings required to cover the IDR tax bomb.

Home & DIY

Induction Conversion Payback Calculator

See how quickly utility, ventilation, and rebate savings repay the upfront cost of switching a kitchen from gas to induction.

Finance

Inflation Adjusted Price

Estimate a future price after inflation.

Finance & Business

Retirement Savings with Inflation Calculator

Use this calculator to estimate the future value of your current savings after accounting for annual returns and inflation.

Web & Marketing

Micro vs Macro Influencer ROI Comparison

Quantify whether micro-influencer collaborations yield better returns than a macro placement by comparing cost, conversions, and conversion value. Use the output to justify creator mixes and budget reallocations.

Home & DIY

Insulation Optimal Thickness Calculator

Determine the insulation thickness needed to reach a target R-value and estimate project cost based on material conductivity, area, and existing insulation.

Home & DIY

Insulation Roll Count Calculator

Figure out how many insulation rolls to purchase based on area coverage.

Finance & Business

Interest Coverage Ratio

Determine how comfortably earnings before interest and taxes can cover interest obligations.

Home & DIY

Interior Paint VOC Emissions Calculator

Estimate how much volatile organic compound (VOC) mass is released from paint and how long to ventilate for a 90% reduction at a given air exchange rate.

Health & Fitness

Intermittent Fasting Schedule Planner

Determine how to space meals once your fasting period ends. Enter the number of fasting hours each day and how many meals you intend to eat during the feeding window to see the recommended spacing between meals.

Health & Fitness

Intermittent Fasting Window Designer

Plan fasting and eating windows around a chosen first meal, including hydration reminders and meal spacing guidance.

Finance

Internal Rate of Return Calculator

Estimate the annualized return that makes the net present value of an investment zero by comparing the starting outlay and the ending value across a set number of periods.

Finance & Business

Inventory Reorder Point Calculator

Determine the stock level at which you should reorder inventory to avoid stockouts.

Finance & Business

Inventory Turnover Ratio Calculator

Measure how efficiently a business sells and replaces its inventory over a given period.

Finance & Business

Invoice Factoring Effective APR Revealer

Convert factoring fees, advance rate, and collection window into an annualized APR.

Finance

Invoice Late Fee

Calculate late fees on overdue invoices.

Technology

IPv4 Subnet Host Count Calculator

Number of usable hosts in an IPv4 subnet.

Technology & Coding

IPv6 Subnet Address Count

Calculate the exact number of assignable IPv6 addresses available for any CIDR prefix length.

Home & DIY

IRA Home Energy Rebate Stacking Calculator

Layer Inflation Reduction Act state rebates with federal tax credits to reveal net project cost, total incentives, and simple payback from annual energy savings.

Date & Time

ISO Week Number Calculator

Determine the ISO 8601 week number for a given date. Enter year, month, and day.

Health & Fitness

IVF Medication Out-of-Pocket Budget Calculator

Estimate IVF medication out-of-pocket costs after insurance coverage, discount programs, and monitoring fees for each cycle.

Health & Fitness

IVF Refund Program Break-Even Analyzer

Compare IVF refund packages against paying per cycle by modeling success odds, partial refunds, and cost per live birth.

Health & Fitness

Jet Lag Recovery Time

Estimate days needed to recover from time zone changes.

Lifestyle & Travel

Jet Lag Synchronization Planner

Build a personalised schedule to shift sleep, light, and melatonin timing based on flight duration and time zone gap.

Date & Time

Jiffies to Seconds

Translate jiffies—short intervals used in computing and electronics—into standard seconds.

Date & Time

Julian Date Converter

Calculate the Julian Day Number for any given calendar date.

Technology

KB to MB Converter

Convert kilobytes to megabytes.

Conversions & Units

Kelvin to Rankine Converter

Convert temperatures from Kelvin to the Rankine scale.

Web & Marketing

Keyword Density Calculator

Calculate keyword density percentages to balance SEO optimization with natural, reader-friendly copy.

Conversions

Kilograms to Grams Converter

Convert kg to g.

Conversions

Kilograms to Pounds Converter

Convert kilograms to pounds.

Conversions

Kilograms to Newtons

Convert mass in kilograms to weight force in Newtons.

Conversions & Units

Kilojoules to Kilocalories Converter

Convert energy from kilojoules to kilocalories. Enter kilojoules and calculate.

Conversions & Units

Kilometers to Nautical Miles Converter

Convert a distance value in kilometers to nautical miles using the factor 1 nmi = 1.852 km.

Home & DIY

Kitchen Remodel Equity Recovery Planner

Estimate the equity added by a kitchen remodel after financing interest costs are repaid.

Conversions

Kilometers to Miles

Convert kilometers into miles.

Other

Knitting Yarn Length

Estimate the total yarn length needed for a knitting project.

Nutrition

Kombucha Fermentation Time Planner

Plan primary kombucha fermentation with a temperature-aware schedule. Balance ambient temperature, starter percentage, tea strength, and target acidity to know when to taste, bottle, or move to secondary fermentation.

Conversions

Kilopascals to PSI Converter

Convert pressure from kilopascals to pounds per square inch.

Technology & Coding

Kubernetes Rightsizing Savings Calculator

Estimate monthly savings from aligning pod CPU and memory requests with observed usage and FinOps guardrails.

Conversions & Units

kVA ↔ kW Power Factor Converter

Translate between apparent power in kVA and real power in kW using the power factor and optional design headroom.

Conversions & Units

kWh to MJ Converter

Convert kilowatt-hours to megajoules.

Health & Fitness

Labor Hydration Calculator

Approximate water intake for manual labor based on body weight, duration, and temperature.

Health & Fitness

Lactate Threshold Pace & Heart Rate Estimator

Translate the results of a 20–30 minute time-trial into actionable training targets. Enter the distance you covered, the total time, and your measured resting and maximum heart rates to see a recommended lactate threshold pace and heart rate.

Home & DIY

Ladder Length Calculator

Find the ladder length needed to reach a height from a set distance.

Finance & Business

Latin America Severance Pay Estimator

Estimate statutory severance packages for select Latin American countries (Mexico, Argentina, Colombia, Chile, Peru). Enter salary, tenure, and unused vacation to view a formatted payout breakdown.

Date & Time

Launch Backward Planner

Work backward from a launch date to see when preparation must start, including buffers.

Other

Laundry Cost Per Load

Calculate the combined water and electricity cost of washing one load of laundry in your home.

Home & DIY

Lawn Mowing Time

Estimate how long it will take to mow a lawn based on area, mower width, and walking speed.

Home & DIY

Lawn Watering Time Calculator

Estimate how many minutes are required to water a lawn to a desired depth. Enter area, desired water depth, and sprinkler flow rate, then press Calculate.

Date & Time

Layover Duration Calculator

Find the time between connecting flights.

Science & Engineering

LC Resonant Frequency Calculator

Calculate the resonant frequency where inductive and capacitive reactances cancel in an LC circuit.

Math & Statistics

LCM Calculator

Compute the smallest common multiple shared by two integers.

Math & Statistics

LCM of Three Numbers

Find the least common multiple of three integers.

Health

Lean Body Mass Calculator

Estimate lean body mass using the Boer formula.

Date & Time

Leap Year Checker

Identify whether a specific year includes an extra day (February 29) by applying the Gregorian leap year rules.

Home & DIY

LED Savings Calculator

Estimate energy cost savings by replacing incandescent bulbs with LEDs.

Science & Engineering

LED Series Resistor Calculator

Calculate the resistor required for an LED circuit using supply voltage, LED forward voltage, and desired current in milliamps.

Home & DIY

LED Strip Current Calculator

Required current for an LED strip.

Education & Learning

Leitner Spaced Repetition Planner

Plan your Leitner flashcard rotations by specifying when you begin, how often Box 1 repeats, and how many boxes you use.

Date & Time

LEO Satellite Visibility Window

Forecast the observable portion of a low-Earth-orbit pass by combining altitude, elevation limits, and twilight conditions.

Science & Engineering

Levelized Cost of Storage (LCOS) Calculator

Discount capital, replacement, and operating costs against delivered energy to find the true cost per megawatt-hour of a battery or thermal storage project.

Math

Lever Mechanical Advantage Calculator

Compute mechanical advantage of a lever.

Home & DIY

Light Pollution & Bortle Improvement

Estimate sky-brightness gains and resulting Bortle class after cutting lumens, adding shielding, and trimming runtime.

Date & Time

Light Travel Time Calculator

Compute time for light to travel a distance in space.

Lifestyle & Travel

Lightning Distance Calculator

Approximate how far lightning struck by multiplying the seconds until thunder by the speed of sound in air (0.343 km/s).

Math & Statistics

Linear Regression Calculator

Enter the number of observations plus the summed products needed for simple linear regression to predict a y value for any target x. The result follows the least-squares best-fit line for your summarized dataset.

Math & Statistics

Linear Regression Prediction Interval

Compute a future value interval for simple linear regression using the point estimate, residual standard error, sample size, and leverage.

Science & Engineering

Liquid Cooling Load Fraction Calculator

Estimate how much IT heat a liquid cooling loop captures versus air systems, along with the remaining air-handled load.

Conversions

Liters per 100 km to MPG Converter

Convert fuel consumption from liters per 100 kilometers to miles per gallon.

Conversions & Units

Liters to Gallons Converter

Convert liquid volumes from liters to US gallons quickly and accurately.

Conversions

Liters to US Fluid Ounces

Convert liters to US fluid ounces.

Technology & Coding

Live Streaming Bandwidth Calculator

Determine the required upload bandwidth to stream at a given bitrate to many viewers.

Technology & Coding

LLM Context Token Cost Forecaster

Forecast API spend for long-context large language model calls with per-1K token pricing.

Technology & Coding

LLM Inference Carbon Intensity Calculator

Quantify grams of CO2e emitted per 1,000 generated tokens using your cluster's power draw, workload throughput, and grid carbon intensity.

Technology & Coding

LLM Inference Infrastructure Cost

Convert traffic, token throughput, and GPU pricing into a monthly infrastructure cost and total GPU hours required.

Technology & Coding

LLM Token Cost Estimator

Estimate API spending by combining prompt and completion token counts with per-1K token pricing.

Technology & Coding

LLM Training Compute Cost Calculator

Project the total cost of fine-tuning large language models by combining GPU runtime, electricity, and contingency overheads.

Technology & Coding

LLM Training Run Budget Calculator

Forecast the all-in cash required for an LLM training or fine-tuning run across GPU, data prep, storage, and egress.

Web & Marketing

Loan Campaign Cost-per-Booked-Loan Optimizer

Convert CPC, funnel conversion rates, and target economics into cost per funded loan and allowable CPA goals.

Personal Finance & Loans

Loan Extra Payment Time Saved

Estimate months saved by adding extra to loan payments.

Finance

Loan Payment Calculator

Determine the fixed monthly payment to repay a loan at a given interest rate and term.

Math & Statistics

Loan Portfolio Default Stress Simulator

Scale base default expectations by a macro stress multiple to estimate charge-offs, loss rates, and buffer gaps.

Finance

Loan-to-Value Ratio Calculator

Find the loan-to-value percentage for a property.

Web & Marketing

Local Services Ads Bid Ceiling Analyzer

Convert job value, close rate, and refund risk into a defensible maximum cost per lead and budget for Google Local Services Ads.

Science & Engineering

Local Supply Chain Resilience Score

Combine supplier count, lead times, safety stock, geopolitical risk, and dual sourcing to benchmark supply chain resilience in percentage terms.

Math

Logarithm Base Conversion

Convert log base using natural logarithms.

Math & Statistics

Logistic Regression Probability Explorer

Convert logistic regression coefficients and feature values into an easy-to-read predicted probability.

Health & Fitness

Long-Term Care Elimination Period Bridge Calculator

Estimate how much cash you need to cover care costs during a long-term care policy elimination period before benefits begin.

Finance

Loss Recovery Percentage

Find the gain needed to recover from a portfolio drop.

Other

Lottery Expected Value

Calculate the expected monetary value of a lottery ticket.

Entertainment

Lottery Winning Probability Calculator

Calculate the probability of winning by matching all numbers in a lottery draw.

Lifestyle & Travel

Luggage Volumetric Weight

Calculate airline volumetric weight from bag dimensions.

Conversions & Units

Lux to Foot-Candles Converter

Convert light level from lux to foot-candles. Enter the lux value and press Calculate.

Conversions & Units

Lux to Lumens Calculator

Determine total luminous flux by multiplying illuminance in lux by the lit area in square meters.

Lifestyle & Travel

Luxury Cruise Onboard Credit Planner

Stack onboard credit against discretionary cruise spending to see coverage, leftover funds, and daily out-of-pocket costs.

Health & Fitness

Macro Rotation Planner

Generate training-day and recovery-day macro targets from body weight, calorie swing, and preferred fat ranges.

Health & Fitness

Macronutrient Distribution Calculator

Enter your daily calorie target and desired macro percentages to see grams of protein, carbohydrates and fats.

Math & Statistics

Mann–Whitney Sample Size Calculator

Estimate how many participants you need per group for a Mann–Whitney U test based on desired power, alpha, and probability of superiority.

Lifestyle & Travel

Map Scale Distance Calculator

Convert a measured length on a map to real-world distance using the map scale.

Finance

Markup/Margin Calculator

Compute selling price from cost and margin.

Date & Time

Mars Sol to Earth Days

Convert Martian sols—Martian days about 39 minutes longer than Earth days—into their Earth-day equivalents.

Web & Marketing

Mass Content Indexation Rate Forecast

Forecast how much of a large batch of new URLs will reach search indexation by weighing authority, internal linking, freshness cadence, and technical hygiene.

Math

Division Calculator

Divide one number by another to find the quotient.

Health

Maximum Heart Rate Calculator

Estimate your maximum heart rate based on age.

Conversions & Units

MB to GB Converter

Convert megabytes to gigabytes for quick storage planning.

Education & Learning

MCAT Percentile Converter

Enter your section scores to estimate the latest MCAT percentile based on the combined total.

Math & Statistics

Mean Absolute Deviation Calculator

Average distance of numbers from their mean.

Health

Mean Arterial Pressure

Estimate average arterial pressure using systolic and diastolic readings.

Science & Engineering

Mean Kinetic Temperature Calculator

Quantify the weighted thermal stress experienced by temperature-sensitive pharmaceuticals and biologics using the official mean kinetic temperature equation.

Math & Statistics

Median of Three Numbers

Find the median value among three numbers.

Personal Finance & Loans

Medical Bill Negotiation Savings Calculator

Project the impact of a negotiated discount and payment plan on your medical debt, monthly payment, and interest costs.

Lifestyle & Travel

Medical Evacuation Membership Value Calculator

Compare medevac membership fees against evacuation probability to reveal expected savings, break-even odds, and annual value.

Personal Finance & Loans

Medicare IRMAA Surcharge Avoidance Planner

Estimate monthly IRMAA surcharges for Medicare Part B and D, then gauge the MAGI reduction needed to fall back to a lower tier.

Date & Time

Medication Schedule Coverage

See how many days your medication will last based on doses and interval.

Lifestyle & Travel

Medication Supply Duration

Enter the number of pills you have and how many you take per day to find out how long your supply will last. Useful for planning refills and managing prescriptions.

Environment

Meeting Carbon Footprint Delta Calculator

Quantify how much carbon your team saves when pivoting from an in-person gathering to a virtual meeting. Add up flights, hotels, and call energy so you can communicate avoided emissions in sustainability reports.

Date & Time

Meeting Cost & Productivity Recovery

Quantify monthly and annual meeting costs plus the dollars and hours you reclaim by trimming frequency or duration.

Productivity

Meeting Cost Calculator

Estimate the true wage cost of a meeting by combining its length, attendee count, and average hourly compensation.

Technology & Coding

Meeting-Free Day Focus Impact Calculator

Quantify the cash savings and reclaimed focus hours delivered by instituting a regular meeting-free day.

Date & Time

Meeting Time Percentage

See how much of your workday is spent in meetings.

Personal Finance & Loans

Mega Backdoor Roth Advantage Calculator

Compare mega backdoor Roth conversions with leaving after-tax 401(k) dollars in a taxable brokerage over your time horizon.

Technology & Coding

Megapixels Calculator

Convert image dimensions into megapixels to evaluate camera sensors, print sizes, and digital file requirements.

Health & Fitness

Menopause HRT Protocol Planner

Estimate a starting estradiol patch dose using age, vasomotor symptom severity, and recent hormone labs.

Science & Engineering

Meteor Shower Observed Rate

Translate published ZHR values into realistic meteors-per-hour counts using your radiant altitude, limiting magnitude, and sky obstruction.

Conversions & Units

Meters per Second to Knots Converter

Convert speeds from meters per second to nautical knots.

Conversions

Meters to Feet Converter

Convert meters to feet with a single factor.

Conversions

Meters to Feet Converter

Convert meters to feet instantly.

Science & Engineering

Upstream Methane Leak Intensity Calculator

Compare detected methane leak rates against gas production volumes to report intensity, tonnage, and CO₂e impact.

Date & Time

Metric Week Converter

Convert standard days into metric weeks of 10 days.

Technology & Coding

MFA Rollout ROI & Risk Reduction Calculator

Quantify breach losses avoided, ROI, payback, and residual risk after rolling out multi-factor authentication.

Date & Time

Microfortnight to Seconds

Quickly convert microfortnights—a playful unit equal to one-millionth of a fortnight—into plain seconds.

Science & Engineering

Microgrid Islanding Runtime Calculator

Estimate how many hours a microgrid can operate in island mode by combining usable storage, critical load, and supplemental generation.

Lifestyle & Travel

Mileage Run PQP Efficiency

Convert fare cost, flown miles, status multiplier, and card bonuses into PQP earned and cost per PQP for status runs.

Conversions

Miles to Kilometers Distance Converter

Instantly transform miles into kilometers for travel planning, race training, and navigation tasks.

Conversions & Units

Millimeters to Inches Converter

Convert measurements from millimeters to inches.

Date & Time

Milliseconds to Days Converter

Convert duration from milliseconds to days.

Date & Time

Minutes to Hours Converter

Convert minutes into decimal hours.

Date & Time

Minutes to Seconds Calculator

Convert minutes to seconds.

Date & Time

Minutes Until Midnight Calculator

Calculate the number of minutes remaining until the next midnight using a 24-hour clock.

Math & Statistics

Modulo Calculator

Compute the non-negative remainder after dividing one number by another.

Personal Finance & Loans

Monthly Savings Contribution Calculator

Determine monthly deposit needed to reach a savings goal.

Finance

Monthly Savings Required

Monthly deposit needed to reach a savings goal.

Date & Time

Months to Weeks

Approximate weeks contained in a number of months.

Personal Finance & Loans

Mortgage Affordability Calculator

Estimate the maximum mortgage loan you can afford based on income, debts, interest rate, and term.

Personal Finance & Loans

Biweekly Mortgage Recast Accelerator

Project payoff time, interest saved, and payback when pairing biweekly payments with periodic recasts.

Finance

Mortgage Points Cost Calculator

Estimate how much cash is needed to buy discount points when closing on a mortgage.

Personal Finance & Loans

Mortgage Points ROI Calculator

Compare buying mortgage discount points versus keeping the standard rate to see breakeven and long-term savings.

Personal Finance & Loans

Mortgage Refinance Break-even Calculator

Determine the number of months required for monthly savings to offset refinancing closing costs.

Personal Finance & Loans

Mortgage Temporary Buydown ROI Calculator

Compare monthly payment relief from a temporary mortgage buydown against the upfront premium, ROI, and payback window.

Home & DIY

Moving Box Count

Estimate how many boxes you need for a move.

Conversions & Units

MPG to L/100km

Convert miles per gallon to liters per 100 kilometers.

Conversions & Units

MPH to KPH Converter

Convert miles per hour to kilometers per hour.

Conversions

MRR to ARR Converter

Convert monthly recurring revenue to annual recurring revenue.

Home & DIY

Mulch Volume

Estimate how many cubic yards of mulch are needed based on coverage area and desired depth. Input the area in square feet and depth in inches to plan your order.

Technology & Coding

Multi-Cloud Egress Cost Optimizer

Estimate monthly data-transfer spend across AWS, Azure, and Google Cloud with cache hit rates and discount programs.

Web & Marketing

Multi-Touch Attribution Payback Forecaster

Forecast incremental revenue, ROI, and payback period from a multi-touch attribution platform investment.

Finance & Business

Multichannel CAC Payback Calculator

Work out how many months it takes blended acquisition spend to pay back once qualified pipeline, win rate, and gross margin are applied.

Conversions

Nautical Miles to Kilometers Converter

Convert nautical miles to kilometers.

Finance & Business

Net Dollar Retention (SaaS) Calculator

Measure how well recurring revenue is retained after accounting for upgrades, downgrades, and churn within a given period.

Finance & Business

Net Present Value Calculator

Estimate the net present value of equal recurring cash flows.

Finance

Net Profit Calculator

Work out your company's net profit by subtracting total expenses from total revenue, using consistent currency inputs and clear guidance on what to include.

Finance & Business

Net Profit Margin Calculator

Measure bottom-line profitability by comparing net revenue to total expenses. Enter period revenue and expenses to return the net profit margin percentage and net income figure.

Finance & Business

Net Revenue Retention Driver Mix Calculator

Break down expansion, contraction, and churn contributions to net revenue retention and quantify the gap to a target NRR.

Finance & Business

Net Revenue Retention Scenario Planner

Model net revenue retention from expansions, downgrades, and churn, and see the expansion needed to hit a target.

Finance & Business

Net Revenue Retention Scenario Builder

Model net revenue retention, end-of-period ARR, and incremental revenue from expansion, contraction, and churn.

Personal Finance & Loans

Net Worth Calculator

Track your personal net worth by subtracting total liabilities from total assets.

Web & Marketing

Newsletter Sponsorship Break-Even

Calculate the CPM, CPC, CPA, and per-issue fee required from newsletter sponsors to cover production time and conversion goals.

Web & Marketing

Newsletter Sponsorship Pricing

Turn subscriber engagement metrics into a recommended sponsorship price per slot and overall package value.

Date & Time

Next Full Moon Calculator

This calculator approximates the number of days until the next full moon. Enter a date to get an estimate based on the average lunar cycle.

Health

Noise Exposure Limit Calculator

Estimate the maximum recommended exposure time for a specific workplace noise level using OSHA's 5 dB exchange rate.

Math & Statistics

Nth Root Calculator

Find real-number nth roots with safeguards for zero or negative bases, clear guidance on valid inputs, and worked examples.

Technology & Coding

Observability Cost per Microservice

Roll up logs, metrics, traces, dashboards, and extras to see the monthly observability bill for a single service.

Other

Occupancy Load Calculator

Estimate maximum occupants based on room area.

Finance & Business

OECD Pillar Two Top-Up Tax Exposure

Model jurisdictional top-up tax under OECD Pillar Two by comparing effective rates with the 15% minimum and carve-outs.

Technology & Coding

Ohm's Law Current

Compute current from voltage and resistance.

Technology & Coding

Ohm's Law Power

Compute power in watts using voltage and current values.

Technology & Coding

Ohm's Law Resistance Calculator

Determine electrical resistance using voltage divided by current. Enter voltage and current and press Calculate.

Technology

Ohm's Law Voltage

Compute voltage from current and resistance using Ohm's Law.

Nutrition

Omega-3 to Omega-6 Ratio Calculator

Enter your daily intake of Omega-3 and Omega-6 fatty acids to see their ratio.

Date & Time

On-Call Rotation Planner

Quickly assign rotating on-call coverage without spreadsheets. Enter your team, start date, and shift length to receive a sequenced schedule.

Health & Fitness

One-Rep Max (Brzycki) Calculator

Estimate your one-repetition maximum using the Brzycki equation.

Health & Fitness

One-Rep Max Calculator

Estimate your one-repetition maximum using the Epley formula.

Finance & Business

Operating Expense Ratio Calculator

Find operating expenses as a percentage of revenue.

Finance & Business

Operating Profit Margin Calculator

Determine the percentage of revenue remaining after covering operating expenses.

Personal Finance & Loans

Optimal Auto Insurance Deductible Calculator

Compare premium savings against expected claim losses and cash reserves to pinpoint the smartest auto deductible.

Lifestyle & Travel

Optimized Baggage Allowance Calculator

Balance carry-on, checked, and personal item weights against airline limits, estimate potential fees, and highlight how much weight to redistribute.

Science & Engineering

Orbital Period Calculator

Use Kepler's third law to estimate how long an object takes to complete an orbit around a central mass.

Web & Marketing

Organic CTR by Position Forecast

Estimate organic click-through rate by rank and SERP layout, and quantify the click gap against current performance.

Conversions & Units

Ounces to Cups Converter

Convert a volume in US fluid ounces to cups using 1 cup = 8 fl oz.

Conversions & Units

Ounces to Milliliters

Convert U.S. fluid ounces to milliliters for travel bottles.

Date & Time

Overtime Hours Calculator

Calculate overtime hours beyond regular schedule.

Finance & Business

Overtime Pay Calculator

Estimate earnings from overtime hours.

Technology & Coding

Packet Loss Percentage Calculator

Calculate the percentage of lost packets by comparing sent and received counts.

Web & Marketing

Page Speed Revenue Impact Estimator

Estimate monthly revenue lift from faster page loads based on conversion uplifts per second saved.

Web & Marketing

Paid Search Brand Defense ROI Calculator

Evaluate whether bidding on branded keywords protects incremental conversions at an efficient CPA.

home-diy

Paint Cost Estimator

Estimate how much a paint project will cost based on area, paint coverage and price per gallon.

Home & DIY

Paint Drying Time

Estimate drying time based on humidity.

Home & DIY

Paint Needed Calculator

Estimate how many liters of paint you need based on surface area, product coverage, and desired number of coats.

Lifestyle & Travel

Paper Roll Length Calculator

Estimate the length of paper on a roll.

Technology

Parallel Resistance

Equivalent resistance of two resistors in parallel.

Other

Parking Space Requirement Calculator

Estimate number of parking spaces based on floor area.

Math & Statistics

Part of Total Percentage

Calculate what percentage a value represents of a whole.

Conversions & Units

Pascal to mmHg Converter

Convert pressure values from pascals to millimeters of mercury using the standard conversion factor 1 mmHg = 133.322 Pa.

Technology & Coding

Password Crack Time Calculator

Estimate time to brute-force a password given entropy and guess rate.

Technology & Coding

Password Entropy Calculator

Calculate the estimated entropy of a password in bits based on its length and character set size.

Web & Marketing

Pay-Per-Call Insurance ROAS

Model lifetime value, breakeven CPL, and return on ad spend for insurance pay-per-call campaigns.

Finance & Business

Payback Period Calculator

Estimate years to recover an initial investment.

Finance & Business

Payment Terms Extension ROI Calculator

Estimate the liquidity unlocked, cost of capital saved, and discount trade-offs when extending supplier payment terms.

Math & Statistics

Pearson Correlation Significance

Calculate the t statistic and two-tailed p-value for a Pearson correlation using sample size.

Finance

Percentage Discount Calculator

Calculate the final price after a percentage discount.

Math & Statistics

Percentage Error Calculator

Find the percent error between a measured quantity and its true value.

math

Percentage Increase

Calculate the percentage gain from an original value to a new value.

Conversions & Units

Percentage to Decimal Converter

Convert any percentage to its decimal form for math, finance, coding, or data analysis.

Math & Statistics

Permutation Calculator

Find the number of ordered arrangements of r items selected from n distinct items.

Science & Engineering

Personal Carbon Budget Pathway Calculator

See the annual emissions reduction needed to reach your long-term personal carbon target by the chosen year.

Science & Engineering

PFAS GAC Changeout Scheduler

Project granular activated carbon changeout timing using influent PFAS levels, target effluent limits, EBCT, and flow.

Science & Engineering

pH from Concentration Calculator

Calculate the pH of a solution from its hydrogen ion concentration.

Technology

Photo Storage Calculator

Estimate storage space needed for digital photos.

Technology

Ping Distance Estimator

Approximate signal distance from round-trip ping time.

Finance & Business

Pipe Installation Cost

Compute material and labor costs for installing piping.

Finance & Business

B2B Pipeline Coverage Planner

Work out how many active opportunities you need to protect your revenue goal based on win rate, average deal size, and the coverage multiple you target.

Date & Time

Pitman 2-2-3 Shift Planner

Quickly translate the Pitman 2-2-3 pattern into staffing metrics. Provide your shift length, how many on-duty shifts each employee works within the 14-day cycle, the total cycle length, and the number of crews to view average weekly hours per employee and total daily staffed hours.

Conversions

Pixels to Centimeters

Convert pixels to centimeters using DPI.

Lifestyle & Travel

Pizza Slice Angle

Divide a pizza evenly by calculating the degrees per slice, with tips for party planning and different slice counts.

Education & Learning

Planetary Light-Travel Time

Convert Earth–target distances into one-way or round-trip light time with optional safety margins for mission planning.

Home & DIY

Plant Spacing Calculator

Determine how many plants fit in a garden bed by combining bed size with the spacing recommended for your crop.

Science & Engineering

Household Plastic Waste Impact Calculator

Enter weekly plastic waste and recycling rate to estimate annual plastic sent to landfills.

Conversions & Units

PM2.5 to AQI Converter

Translate microgram-per-cubic-meter readings from sensors or monitors into the Air Quality Index category for quick risk assessment.

Personal Finance & Loans

PMI Monthly Payment Calculator

Estimate monthly private mortgage insurance cost from loan amount and PMI rate.

Science & Engineering

PMV/PPD Thermal Comfort Calculator

Estimate Predicted Mean Vote (PMV) and Percentage of People Dissatisfied (PPD) using ISO 7730 inputs for air temperature, humidity, clothing, and metabolic rate.

Math

2D Point Distance Calculator

Measure the straight-line distance between two coordinates on a 2D plane for navigation, mapping, or geometry problems.

Lifestyle & Travel

Points & Miles Redemption Value Optimizer

Measure the cents-per-point you unlock by redeeming loyalty currencies after factoring taxes, transfer bonuses, and rebates.

Math & Statistics

Poisson Probability Calculator

Compute Poisson distribution probabilities for event counts.

Health & Fitness

Polarised 80/20 Microcycle Designer

Split weekly training hours into low- and high-intensity buckets using the 80/20 model and session preferences.

Math

Polygon Diagonals Calculator

Number of diagonals in an n‑sided polygon.

Math & Statistics

Polygon Exterior Angle Calculator

Compute the exterior angle of a regular polygon by dividing 360° by the number of sides.

Math & Statistics

Polygon Interior Angle Sum

Total degrees of a polygon's interior angles.

Math & Statistics

Polynomial Roots Calculator

Enter coefficients for a polynomial up to degree four to compute all real and complex roots.

Date & Time

Pomodoro Session Duration

Calculate the total time required for a set of Pomodoro work sessions including short breaks.

Health & Fitness

Ponderal Index Calculator

Evaluate body build with the Ponderal Index, a height-cubed alternative to BMI.

Home & DIY

Pool Evaporation Rate Calculator

Estimate daily pool water loss in litres using surface area, temperature, humidity, and wind speed. Plan top-ups, cover strategies, and chemical adjustments based on local weather conditions.

Home & DIY

Pool Maintenance Cost Calculator

Add up chemicals, energy, supplies, and service extras to forecast your annual residential pool upkeep budget.

Home & DIY

Post Hole Concrete Calculator

Volume of concrete needed for a cylindrical post hole.

Conversions & Units

Pounds to Kilograms Converter

Convert pounds (lb) to kilograms (kg).

Conversions & Units

Pounds to Stones Converter

Convert a weight in pounds to stones. Enter the value and press Calculate.

Technology & Coding

Power Bank Recharges

Estimate how many times a power bank can charge your device.

Math & Statistics

Power Set Size Calculator

Determine the size of a power set by raising 2 to the number of elements.

Technology & Coding

Power Supply Efficiency Calculator

Determine PSU efficiency from output and input power.

Conversions & Units

PPM to Pounds per Acre Converter

Convert soil test results from parts per million to pounds of nutrient per acre.

Health & Fitness

Pregnancy Due Date Calculator

Estimate expected due date 280 days from the last menstrual period.

Health & Fitness

Pregnancy Week Calculator

Estimate gestational age in weeks from your last menstrual period and today's date to track prenatal milestones with clarity.

Lifestyle & Travel

Premium Cabin Miles vs Cash Value Calculator

See whether redeeming miles for a premium cabin ticket beats paying cash once taxes, rebates, and opportunity cost are considered.

Lifestyle & Travel

Premium Cabin Upgrade Bid ROI Estimator

Value cash upgrade bids by factoring in fare differences, elite perks, and comfort assumptions for long-haul flights.

Finance

Present Value (Single Cash Flow)

Discount a future amount back to today's value.

Math & Statistics

Prime Factorization Calculator

Enter an integer to see its prime factors expressed in a multiplication sequence.

Technology & Coding

Printer Cost per Page

Determine how much each printed page costs based on cartridge price and yield.

Lifestyle & Travel

Printing Carbon Footprint

Approximate CO₂ emissions using 0.0044 kg per printed page.

Finance & Business

Private Equity Preferred Return Catch-Up Calculator

Project preferred return shortfalls, GP catch-up pools, and the next distribution split for a private equity waterfall.

Personal Finance & Loans

Private Student Loan Refinance Breakeven Calculator

Project the net lifetime savings from refinancing a private student loan after closing costs.

Lifestyle & Travel

Private Villa Buyout vs Luxury Resort ROI Calculator

Compare per-guest costs and total spend between a private villa buyout and equivalent luxury resort suites.

Finance & Business

Product Cannibalization Impact Simulator

Forecast the net annual gross profit from a new SKU once you subtract margin cannibalised from the legacy offer.

Web & Marketing

Programmatic Ad Viewability Lift Planner

Forecast incremental viewable impressions and revenue lift when raising average viewability across your ad inventory.

Web & Marketing

Programmatic SEO Revenue Calculator

Project net monthly revenue from programmatic SEO pages using search volume, CTR, conversions, and ad RPM.

Science & Engineering

Projectile Range Calculator

Calculate ideal projectile range from launch speed, angle, and gravity to support physics homework, engineering projects, and sports analytics.

Conversions & Units

Proof to ABV Converter

Convert between alcohol proof and ABV for US and UK scales by selecting the direction and system.

Math & Statistics

Propensity Score Matching Power Calculator

Estimate statistical power for matched treated and control cohorts, then see how many controls you need to hit 80% power.

Home & DIY

Property Tax Assessment Appeal Savings Estimator

Estimate annual tax savings, payback, and multi-year upside before filing a property tax assessment appeal.

Health

Protein Calorie Percentage

Percentage of calories coming from protein.

Conversions

PSF to kPa Converter

Convert structural load from pounds per square foot to kilopascals.

Conversions

PSI to kPa Converter

Convert pressure from pounds per square inch to kilopascals.

Technology & Coding

PSU Load Percentage

Check how much of a power supply's capacity your system draws.

Health

Pulse Pressure Calculator

Calculate pulse pressure from systolic and diastolic blood pressure readings.

Science & Engineering

Pumped Thermal Energy Storage Efficiency Calculator

Translate charging and discharging energy balances into gross and net round-trip efficiency for pumped thermal systems.

Date & Time

PVC Cure Completion Time

Estimate when a PVC solvent-weld joint reaches full cure by combining start time and manufacturer-recommended dwell duration.

math

Pythagorean Theorem Calculator

Calculate the hypotenuse of a right triangle. Enter the values and press Calculate.

Technology & Coding

QA Test Automation ROI Calculator

Project the return on investment of automating QA by comparing manual testing hours, automation build effort, maintenance workload, and quality gains.

Math

Quadratic Discriminant

Compute the discriminant D = b² − 4ac.

Math

Quadratic Positive Root

Largest real root of ax² + bx + c = 0.

Math & Statistics

Quadratic Vertex X

Find the x-coordinate of a parabola's vertex with step-by-step context for graphing y = ax² + bx + c, plus tips for interpreting maxima and minima.

Personal Finance & Loans

Qualified Business Income Deduction Phaseout Calculator

Work out the 2024 Section 199A deduction after applying taxable income phase-ins, W-2 wage limits, and UBIA adjustments.

Date & Time

Quarter of Year Calculator

Find the calendar quarter by entering a month number from 1 to 12.

Lifestyle & Travel

Queue Wait Time

Estimate total wait time in a single-file queue by multiplying people ahead by service time per person.

Finance & Business

Quick Ratio Calculator

Assess short-term liquidity by comparing quick assets to current liabilities.

Conversions

R-Value to U-Value Converter

Convert thermal resistance (R-value) into thermal transmittance (U-value) for insulation comparisons and energy-code compliance checks.

Lifestyle & Travel

Rabbit Age to Human Years Calculator

Approximate a rabbit's age in human years using a factor of eight.

Health & Fitness

Race Goal Time Calculator

Provide your current pace, race distance, and anticipated performance gain to estimate a goal finish time.

Health & Fitness

Race Time Calculator

Project your race finish time from distance and target pace so you can plan training runs and pacing strategies.

Conversions & Units

Radians to Degrees Calculator

Convert angle measurements from radians to degrees.

Science & Engineering

Radioactive Decay Remaining

Calculate the remaining quantity of a radioactive substance after a specified time using its half-life.

Science & Engineering

Radiocarbon Dating Calculator

Compute the approximate age of an organic sample using the remaining percentage of carbon-14 compared to a modern reference.

Other

Raffle Win Probability

Chance of winning a single-draw raffle.

Technology & Coding

RAG Query Cost Calculator

Estimate marginal cost per Retrieval-Augmented Generation (RAG) response by combining retrieval width, token usage, cache hit rate, and optional reranker fees.

Technology & Coding

RAG Recall@K Calculator

Evaluate retrieval-augmented generation coverage by comparing relevant documents retrieved in the top-K set to the total ground truth.

Technology & Coding

RAID 5 Capacity Calculator

Compute usable capacity of a RAID 5 array based on drive count and individual drive size.

Home & DIY

Rain Barrel Fill Time

Estimate how long it takes to fill a rain barrel from a hose or pump by combining barrel volume and flow rate, with readable hour/minute outputs.

Home & DIY

Rain Garden Sizing Calculator

Size a residential rain garden by combining catchment area, design storm depth, soil infiltration, and storage depth.

Home & DIY

Rain Gutter Volume Calculator

Estimate water capacity of a gutter section.

Home & DIY

Rainwater Harvest Calculator

Estimate collected rainwater volume from roof size and rainfall.

Home & DIY

Rainwater Harvest Volume

Approximate how much rainwater a roof can collect from a single rainfall event.

Home & DIY

Rainwater Harvesting Tank Sizer

Estimate monthly capture and suggest a cistern size by combining roof area, rainfall, runoff coefficient, and demand.

Date & Time

Rate Lock Expiry Countdown Planner

Project your mortgage rate-lock expiration, remaining buffer to closing, and potential extension costs.

Science & Engineering

RC Time Constant Calculator

Multiply resistance and capacitance to find the RC time constant for timing and filter circuits.

Finance & Business

R&D Tax Credit Payroll Offset Maximizer

Turn qualified research spend into payroll tax offsets, confirm eligibility, and track any credit that carries forward.

Education & Learning

Reading List Completion Time Calculator

Calculate the number of days and weeks required to read through a list based on your daily page pace.

Education & Learning

Reading Pace Planner

Plan how many pages to read each day to complete a book within a target timeframe.

Education & Learning

Reading Speed Calculator

Measure words per minute by combining word count and reading time to benchmark comprehension drills, study sessions, and presentations.

Lifestyle & Travel

Reading Time Estimator

Estimate reading time from word count.

Finance & Business

Real Cumulative Inflation Calculator

Combine a starting price, monthly inflation, and time horizon to forecast nominal and real price changes after adjusting for income or productivity gains.

Lifestyle & Travel

Ream Duration Calculator

Estimate how long a standard 500-sheet ream of paper will last given your daily printing volume.

Lifestyle & Travel

Recipe Scale Factor

Multiplier to scale ingredient quantities.

Math

Rectangle Area Calculator

Compute the area of any rectangle from its length and width, with guidance on unit consistency and practical use cases.

Math & Statistics

Rectangular Prism Volume Calculator

Compute the volume of a rectangular prism from its length, width, and height. Enter the dimensions and press Calculate.

Home & DIY

Remodeling Budget Calculator

Estimate total renovation cost by combining materials, labor, and a contingency percentage.

Lifestyle & Travel

Remote Work Expense Impact Calculator

Measure the monthly savings or extra cost of working remotely by comparing commute spending with home office expenses.

Lifestyle & Travel

Remote Workation Monthly Budget Calculator

Roll housing, workspace, daily living, excursions, and contingency buffers into a monthly USD budget for remote workations.

Technology

Render Time

Estimate total render time for animations.

Personal Finance & Loans

Rent-to-Income Ratio Calculator

Determine what portion of your income is spent on rent. Enter your monthly rent and monthly income to see the percentage.

Personal Finance & Loans

Rent vs Buy Calculator

Estimate whether renting or buying is cheaper over a given period. The calculator compares rent payments with a simplified cost of purchasing a home.

Other

Required Final Exam Score

Score needed on the final to reach a target grade.

Finance

Required Minimum Distribution

Estimate your required minimum distribution from retirement accounts.

Finance & Business

Research Grant Overhead Calculator

Calculate how much of a grant remains after an institution's overhead deduction.

Lifestyle & Travel

Research Poster Font Size

Determine readable font size for academic posters using viewing distance.

Home & DIY

Residential EV Charger Load Planner

Check if your existing service panel can support a Level 2 EV charger alongside current continuous loads.

Home & DIY

Residential Solar Payback & ROI Calculator

Model home solar cash flow with incentives, energy usage, rate escalation, and production forecasts to see net cost, simple payback, and long-horizon ROI in one narrative summary.

Web & Marketing

Retail Media Co-Op Margin Forecaster

Blend co-op matches, ad spend, and incremental sales to see contribution gains or losses from retail media pushes.

Web & Marketing

Retail Media Margin Assurance Calculator

Test whether retail media ad revenue preserves contribution margin after factoring platform fees, promo erosion, and fulfillment drag.

Web & Marketing

Retail Media ROI Lift Calculator

Measure the incremental efficiency of on-site ads, sponsored product listings, or marketplace promotions against your existing acquisition engine. Enter your baseline revenue and spend, the incremental revenue proven by lift studies, and the incremental budget dedicated to retail media to see how much your blended ROI rises or falls.

Finance & Business

Retirement Income Replacement Target

Estimate how much of your current salary will be covered in retirement once you add pensions, annuities, and planned withdrawals.

Finance

Retirement Savings Goal

Estimate the total savings needed for a desired annual retirement income.

Date & Time

Retirement Year Estimator

Find the calendar year you can retire based on birth year and target retirement age.

Web & Marketing

Return on Ad Spend Calculator

Measure revenue return per advertising dollar.

Finance & Business

Return on Assets Calculator

Determine how efficiently a company uses its assets to generate profit.

Finance

Return on Equity Calculator

Calculate return on equity from net income and shareholder equity.

Finance & Business

Return on Investment (ROI) Calculator

Find the percentage return on an investment using initial cost and final value.

Finance & Business

Revenue per Employee Calculator

Calculate how much revenue each employee generates on average. Enter the company's total revenue and the number of employees to find the revenue per employee.

Science & Engineering

Reynolds Number Calculator

Evaluate whether a fluid flow is laminar, transitional, or turbulent by calculating its Reynolds number. Enter density, velocity, characteristic length, and dynamic viscosity.

Lifestyle & Travel

Road Trip Carbon Emissions Calculator

Estimate the carbon dioxide emissions of a road trip by combining distance, vehicle efficiency, and fuel emission factor.

Lifestyle & Travel

Road Trip Cost Splitter

Estimate total road trip expenses and divide them fairly across travellers.

Lifestyle & Travel

Road Trip Fuel Stops

Estimate how many refueling stops are needed on a road trip when starting with a full tank.

Lifestyle & Travel

Road Trip Rest Stops Calculator

Calculate how many rest stops are needed on a road trip based on your maximum comfortable driving distance per leg.

Math & Statistics

Road Trip Time Planner

Calculate how long a road trip will take by combining driving speed, distance, and planned stop durations.

Lifestyle & Travel

Road Trip Toll Cost Calculator

Quickly approximate toll costs by multiplying trip distance by an average rate per kilometer.

Technology & Coding

Roaming Data Cost

Compute the expected charges for mobile data usage while traveling abroad.

Finance

ROI Calculator

Calculate return on investment as a percentage, compare gains against costs, and learn how to interpret positive vs. negative ROI in budgeting decisions.

Finance

ROI Dollar Amount Calculator

Convert ROI percentages into profit dollars so you can quantify projected gains from marketing, product, or capital investments.

Home & DIY

Roof Area Calculator

Estimate the surface area of a simple gable roof. Enter the building footprint dimensions and roof pitch to compute the total roof area.

Home & DIY

Roof Pitch Angle

Convert roof rise and run into pitch angle in degrees.

home-diy

Roof Shingle Bundle Calculator

Estimate bundles of shingles needed for a roof.

Home & DIY

Roof Snow Load Calculator

Estimate weight of snow on a roof.

Home & DIY

Room Cooling BTU (Simple)

Estimate cooling capacity from room area.

Math

Room Diagonal Calculator

Compute the diagonal length of a rectangular room.

Home & DIY

Room Heating BTU Calculator

Estimate required heating output by multiplying room area by a BTU per square foot factor.

Home & DIY

Room Lighting Lumens

Calculate recommended lumens for a room based on area and desired brightness.

Science & Engineering

Room Reverberation Time (RT60) Estimator

Estimate RT60 decay time by combining room dimensions with an average absorption coefficient. Toggle between Sabine and Eyring models to evaluate untreated and highly absorptive spaces.

Personal Finance & Loans

Roth Conversion Tax Impact Calculator

Estimate the combined federal and state income taxes owed when you move money from a traditional retirement account into a Roth IRA. Enter the conversion amount plus the marginal tax rates that will apply this year.

Conversions & Units

RPM to Hertz Converter

Convert rotational speed from revolutions per minute to hertz, understand cycles per second, and learn where the conversion matters in engineering and audio.

Finance & Business

RSU Vesting Tax Planner

Estimate vested RSU shares, tax withholding, and net value based on your schedule and combined tax rates.

Math

Rule of 72 Calculator

Estimate years to double an investment using the rule of 72.

Math & Statistics

Rule of Three Calculator

Enter A, B, and C to solve for X in the proportion A/B = C/X.

Health & Fitness

Running Pace Calculator

Compute your average running pace per kilometer from distance and time.

Technology & Coding

SaaS Feature Adoption Paywall Forecaster

Forecast incremental MRR, conversion sensitivity, and adoption risk before moving a free feature behind a paywall.

Finance & Business

SaaS Magic Number Efficiency Calculator

Compute the SaaS magic number by comparing net new annual recurring revenue (ARR) against the prior quarter's sales and marketing spend. Enter the gross new ARR won this quarter, your churn percentage, and the previous quarter's sales and marketing investment to see the resulting efficiency ratio.

Finance & Business

SaaS Price Increase Impact Calculator

Project post-increase MRR by combining impacted share, churn lift, and upgrade adoption to quantify net revenue.

Finance & Business

SaaS Rule of 40 Calculator

Combine recurring revenue growth and profitability margins to see the SaaS Rule of 40 score for your subscription business.

Other

Safety Incident Rate Calculator

Compute the OSHA recordable incident rate per 100 full-time workers and learn how to benchmark your safety performance.

Finance & Business

Safety Stock & Reorder Point Planner

Calculate safety stock and reorder point in one step using demand variability, service level, and lead time.

Finance

Sales Tax Calculator

Calculate the total price of a purchase after adding a sales tax percentage.

Education & Learning

SAT Superscore Calculator

Enter up to three sets of SAT Math and Evidence-Based Reading & Writing (EBRW) section scores to find your superscore. The calculator selects the highest Math and highest EBRW results and adds them together.

Finance & Business

Savings Goal Timeline Calculator

Estimate months to reach a savings goal.

Personal Finance & Loans

Savings Rate Calculator

Determine what percentage of your income you set aside each year.

Finance & Business

Savings Withdrawal Duration

Calculate how many months your savings can sustain fixed monthly withdrawals. Enter the total amount saved and the monthly withdrawal to estimate the duration of your funds.

Finance & Business

SBA 7(a) Prepayment Penalty Forecaster

Estimate the 7(a) prepayment penalty and compare it with refinancing savings based on the rate drop you expect.

Science & Engineering

Scaffolding Wind Load Calculator

Estimate design pressure and total wind load on temporary scaffolding using wind speed, height, terrain, and screening factors.

Science & Engineering

Scope 1 Stationary Combustion Calculator

Convert fuel energy consumption and emission factors into Scope 1 CO₂e for stationary combustion sources.

Science & Engineering

Scope 2 Market-Based Emissions Calculator

Quantify market-based Scope 2 emissions by pairing contracted energy, residual consumption, and emission factors.

Finance & Business

Scope 3 Purchased Goods Emissions Calculator

Convert procurement spend and emission factors into Scope 3 Category 1 CO₂e, with optional inflation and supplier abatements.

Health & Fitness

Screen Break Frequency

Count how many 20-second eye breaks to take every 20 minutes of screen time.

Technology

Screen PPI Calculator

Pixels per inch from resolution and diagonal size.

Technology & Coding

Screen-to-Body Ratio Calculator

Calculate how much of a device's front face is occupied by the display—perfect for comparing smartphones and tablets.

Date & Time

Seconds to Days Converter

Convert any duration in seconds into days with decimal precision and context on leap seconds, long projects, and scheduling.

date-time

Seconds to Minutes Converter

Convert seconds to minutes.

Date & Time

Seconds to Months Converter

Approximate how many 30-day months fit in a number of seconds.

Date & Time

Seconds to Weeks Converter

Convert seconds to weeks.

Finance & Business

Section 174 Capitalization Cash-Flow Stress Tester

Model the incremental taxable income, cash tax due, and capitalized balance created by Section 174 amortization rules.

Finance & Business

Section 179 vs Bonus Depreciation Planner

Balance Section 179 expensing, bonus depreciation, and MACRS carryforward as phase-out thresholds reduce your deduction.

Health

Sedentary Calorie Burn Calculator

Estimate calories burned while sitting.

Health & Fitness

Semaglutide Titration Planner

Map your weekly semaglutide dose increases, ramp duration, and expected weight milestone based on your goals.

Date & Time

Semester Week Number

Find which week of the semester a specific date falls into based on the term start date.

Science & Engineering

Semiconductor Cleanroom Downtime Cost Calculator

Convert wafer throughput losses and scrap rates into the total financial impact of a cleanroom downtime event.

Science & Engineering

Semiconductor Tool OEE Calculator

Translate availability, performance, and quality for a fab tool into an overall equipment effectiveness (OEE) percentage.

Web & Marketing

SEO Title Tag Pixel Length Checker

Estimate the rendered width of your HTML title tag so it fits within Google's search results snippet. Count uppercase characters, lowercase characters, and spaces or symbols to approximate the total pixel length.

Math & Statistics

Sequential Alpha Spending Planner

Generate O'Brien-Fleming or Pocock alpha-spending boundaries across interim looks to keep cumulative error on target.

Science & Engineering

Serial Dilution Step Planner

Plan the number of dilution steps and pipetting volumes needed to reach a target concentration from a stock solution.

Web & Marketing

SERP Feature Click Share Calculator

Blend baseline click-through rate with the lower CTR observed on SERPs that contain rich features to project total organic clicks.

Science & Engineering

Server Rack Power Density Calculator

Compute kW per rack by combining total IT load, redundancy headroom, and utilisation targets.

Science & Engineering

Server Room Cooling Load Calculator

Estimate BTU per hour, cooling tonnage, and airflow requirements for server rooms using IT, lighting, and occupancy loads.

Technology & Coding

Server Uptime Percentage Calculator

Calculate uptime percentage from hours online and total hours.

Lifestyle & Travel

Shadow Length Calculator

Calculate how long a shadow will be based on object height and sun elevation angle.

Education & Learning

Shared Parental Coverage Planner

Blend parental leave weeks, overlap, external help, and care demand to expose coverage gaps or surpluses across your planning horizon.

Home & DIY

Shelf Load Capacity

Calculate total shelf load based on per-shelf capacity and number of shelves.

Conversions

Sheppey to Meters

Convert sheppeys into meters.

Date & Time

Shift Worker Circadian Alignment Planner

Estimate how many hours and days it will take to align your sleep schedule with a new shift using light exposure and caffeine strategies.

Finance

Shop Labor Cost Calculator

Estimate labor cost from hourly rate and hours.

Lifestyle & Travel

Shower Water Usage Calculator

Estimate water used during a shower.

Date & Time

Sidereal Day to Hours

Convert sidereal days into Earth hours.

finance

Simple Interest Calculator

Compute interest earned with the simple interest formula. Enter the values and press Calculate.

Finance

Simple Interest Calculator

Compute simple interest based on principal, rate and time.

Lifestyle & Travel

Ski Season Pass Break-even Calculator

Determine how many paid ski days it takes for a season pass to break even compared to buying day tickets. Enter the price of the pass and the average walk-up ticket cost.

Technology & Coding

SLA Penalty vs. Latency Investment Calculator

Balance SLA penalty avoidance against infrastructure upgrade spend by modeling latency improvements and ROI.

Health

Sleep Cycle Count

Estimate how many complete 90-minute sleep cycles fit into any planned sleep duration.

Health

Sleep Debt Calculator

Estimate how many hours of rest you owe your body by comparing recommended sleep to actual sleep across days.

Health

Sleep Debt Recovery Planner

Translate accumulated sleep debt into the extra nightly rest you need across your planned recovery nights.

Health

Sleep Debt Weekly

Estimate weekly sleep debt from average nightly rest.

Date & Time

Sleep Duration Calculator

Find hours of sleep between bedtime and wake time.

Health & Fitness

Sleep Efficiency Calculator

Calculate sleep efficiency by comparing actual sleep time to total time spent in bed. Enter hours in bed and hours slept.

Education & Learning

Slides Per Minute Calculator

Determine how many slides you'll present per minute by dividing total slides by total minutes.

Technology & Coding

SLO Error Budget Burn Rate Monitor

Track how quickly your team is consuming the SLO error budget using observed incidents versus the allowed burn window.

Math & Statistics

Slope Between Two Points Calculator

Find the slope of a line through two points.

Technology & Coding

Smart Device Energy Consumption Calculator

Provide device wattage, daily hours of use, and total days to estimate electricity consumption in kilowatt-hours.

Home & DIY

Smart Thermostat Setback Savings Planner

Estimate annual heating or cooling savings from daily temperature setbacks using a rule-of-thumb efficiency factor.

Technology

Smartphone Charge Time

Estimate how long it takes to fully charge a phone battery.

Health & Fitness

Smoking Pack Years

Estimate cumulative smoking exposure by multiplying daily packs by years smoked.

Conversions

Smoots to Meters Converter

Convert the length of smoots into meters.

Conversions

Smoots to Meters

Convert smoots—a playful MIT unit—into meters.

Technology & Coding

SOC 2 Audit Budget Forecaster

Estimate total SOC 2 readiness and audit spend including internal labor and contingencies.

Web & Marketing

Social Media Engagement Rate

Calculate the engagement rate of a social media post by comparing total interactions to follower count.

Web & Marketing

Social Media ROI Calculator

Enter campaign revenue and cost to find ROI as a percentage.

Finance & Business

SOFR Interest Rate Cap Breakeven Calculator

Compare floating-rate interest costs against a SOFR interest rate cap, measure potential savings after the cap premium, and estimate the average rate needed to break even.

Date & Time

Solar Eclipse Visibility

Estimate eclipse obscuration and a practical viewing window by combining Sun and Moon apparent diameters with their centre separation.

Home & DIY

Home Solar Panel Count Calculator

Enter daily energy demand, panel watt rating, and average sun hours to estimate how many panels are required.

Home & DIY

Solar Panel Energy Estimate

Daily energy from solar panels based on wattage and sun hours.

Home & DIY

Solar Panel Savings Calculator

Calculate annual savings by combining sunlight hours, panel wattage, number of panels and electricity cost.

Science & Engineering

Solar Panel Wind Load Calculator

Model design wind load on a photovoltaic module with a simplified ASCE-style equation that multiplies dynamic pressure by exposure and pressure factors.

Home & DIY

Solar PPA vs. Loan Payment Break-Even Calculator

Compare a solar PPA to loan-financed ownership by modeling payments, incentives, escalators, and long-term savings.

Science & Engineering

Solar Storm Radiation Dose

Forecast relative radiation dose when photographing auroras, eclipses, or high-latitude flares. Input the geomagnetic Kp index, planned exposure duration, current 10.7 cm solar radio flux, and your shielding effectiveness to estimate incremental micro-sieverts above background levels.

Lifestyle & Travel

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Browse every calculator

1031 Exchange Boot Liability Estimator

2-2-3 (DuPont) Shift Schedule Planner

3D Print Time & Cost Estimator

3D Print Time Estimator

401(k) Employer Match Calculator

4-3-3 Shift Rotation Scheduler

529-to-Roth Transfer Eligibility Calculator

A1C to eAG Calculator

ABM Webinar Pipeline Payback Calculator

Academic Probation GPA Recovery Planner

Accounts Receivable Turnover Calculator

ACH Target Gap Calculator

Acute:Chronic Workload Ratio

Ad Inventory Floor Price Stress Test

Add Business Days

Add Weeks to Date Calculator

Adjustable-Rate Mortgage Reset Payment Calculator

Affiliate Ads Break-even Calculator

Affiliate Clawback Buffer Calculator

Affiliate Landing Page Profit Gap

Age Calculator

Age in Days Calculator

Age in Hours

Age in Months Calculator

Age in Weeks Calculator

Agrivoltaics Lease Split & Yield Impact Calculator

AI API Usage Break-Even Pricing

AI Inference Cost Calculator

AI Inference GPU Cost Parity Calculator

AI Trust & Safety Moderation Staffing Forecaster

Air Changes per Hour Calculator

Air Conditioner BTU Calculator

Airline Miles Value Calculator

Airport Lounge Membership Value Calculator

Airport Lounge Pass Break-even Tracker

Airport Lounge Payback Calculator

Blood Alcohol Elimination Time Calculator

Altitude Acclimatization Schedule Calculator

Amazon PPC Incremental ROI Calculator

Ambulatory Blood Pressure Load Calculator

Amp-hours to Watt-hours Converter

Annual Work Hours Calculator

Annuity Net Present Value Calculator

API Rate Limit Capacity Planner

API Rate Limit Planner

APR to Flat-Fee Lending Translator

Arc Length of a Circle

Arithmetic Series Sum Calculator

Aspect Ratio Calculator

Asset Turnover Ratio Calculator

Astro Tourism Trip Planner

Attendance Requirement Calculator

Attic Fan Size Calculator

Auto Loan Payment Calculator

Average Speed Calculator

B2B Keyword Intent Profit Forecaster

Backpack Weight Ratio Calculator

Baggage Overweight Fee Calculator

Balance Transfer Break-Even Calculator

Balcony Solar ROI Calculator

Banana Equivalent Dose Converter

Bandwidth Delay Product

Bank Fee Dispute Refund Estimator

Bank Treasury Liquidity Coverage Ratio

Bariatric Surgery Out-of-Pocket Planner

Basal Metabolic Rate

Base64 Encoded Size Calculator

Baseboard Trim Length

Battery Charge Time

Battery Demand Charge Avoidance Calculator

Battery Energy Arbitrage Margin Calculator

Battery Life Calculator

Battery Life Estimator

Battery Round-Trip Efficiency Calculator

Battery Runtime Calculator

Battery State of Charge (SOC) Calculator

Battery State of Health (SOH) Calculator

Battery Storage Frequency Regulation Revenue Planner