Knowledge hub
Units & Measures
The Units & Measures library curates in-depth explainers about the numbers behind everyday life. Dive into the origins of the metric and imperial systems, the evolution of standardisation and the stories of iconic units that shaped science, navigation and trade.
Each guide blends historical insight with modern relevance so you can connect foundational measurement concepts to calculators across CalcSimpler. Use these resources to teach, learn or simply satisfy your curiosity about how we compare, quantify and communicate the world around us.
What you will find
Historical context
Understand how ancient civilizations standardised length, weight and volume to trade reliably.
Practical frameworks
Learn the difference between metric and imperial conventions and when to use each one.
Modern relevance
See how international standards bodies keep science, engineering and commerce aligned today.
Featured articles
Latest measurement insights
Start with the essentials and check back soon for more deep dives into reference standards, conversion bridges and specialised unit stories.
What is a Unit of Measurement?
Define units, trace their origins and see why consistent measurement underpins every field of study.
Global standardsISO 80000-1: General Principles for Quantities and Units
Understand how Part 1 establishes the terminology, typography and base quantities that keep every ISO 80000 chapter aligned.
Global standardsISO 80000-2: Mathematical Signs and Symbols
Learn the notation rules for algebra, calculus and vectors so your calculations match the typography used across ISO 80000.
Global standardsISO 80000-3: Quantities and Units of Space and Time
Dive into the spatial, temporal and kinematic quantities that connect distance, duration and angular motion across the ISO framework.
Global standardsISO 80000-4: Quantities and Units of Mechanics
Study how force, torque, momentum and energy definitions interlock so structural loads and machines stay aligned with SI units.
Global standardsISO 80000-5: Quantities and Units of Thermodynamics
Master the kelvin scale, energy balances, and entropy definitions that power heating, cooling, and energy efficiency studies.
Global standardsISO 80000-6: Quantities and Units of Electromagnetism
Explore the electrical and magnetic field definitions that keep circuitry, power systems, and EMC reports aligned with SI units.
Global standardsISO 80000-7: Quantities and Units of Light and Radiation
Unpack how photometric and radiometric measures tie light measurements to the candela, lumen, lux, and watt for consistent lighting analyses.
Global standardsISO 80000-8: Quantities and Units of Acoustics
Learn how ISO 80000-8 formalises sound pressure, intensity, power and exposure so environmental and product noise studies speak the same language.
Global standardsISO 80000-9: Quantities and Units of Physical Chemistry
Map moles, concentrations, molecular constants and catalytic activity into SI-coherent terms for reproducible lab records and process models.
Global standardsISO 80000-10: Quantities and Units of Atomic and Nuclear Physics
Trace half-lives, decay constants and radiation dose metrics back to their SI roots so safeguards, medical and research teams share consistent data.
Global standardsISO 80000-11: Quantities and Units of Characteristic Numbers
Translate Reynolds, Mach, Prandtl and other similarity ratios into ISO terminology so scale models, simulations and plant data stay comparable.
Global standardsISO 80000-12: Quantities and Units of Solid State Physics
Navigate lattice parameters, elastic constants, transport coefficients and magnetic descriptors with SI-aligned notation for condensed matter work.
Global standardsISO 80000-13: Quantities and Units of Information Science and Technology
Clarify bits, binary prefixes, data rates and reliability metrics so software, networking and analytics teams speak the same measurement language.
Global standardsISO 80000: Quantities and Units (13 Main Parts)
Jump straight into part-by-part tables that map ISO 80000 quantities to their symbols and SI-aligned units.
Global standardsInternational System of Units (SI)
Review the seven base units, the constants that define them and the tools that keep everyday calculations coherent.
Global standardsISO 80000 Quantities & Units
Follow the volumes that codify symbols, prefixes and derived units so engineers, scientists and buyers speak the same measurement language.