Smartphone Charge Time

Enter your phone's battery capacity and your charger's output current to estimate full charge time in hours.

Use the rated capacity from the device specifications—most modern phones range between 3,000 and 5,000 mAh.
Look for the charger's printed USB output, e.g., 2.2 A for a fast charger.

Approximate planning tool only. Battery management software and environmental conditions influence actual charge duration.

Examples

  • 4,500 mAh battery with 2.2 A charger ⇒ 2.05 hours
  • 5,000 mAh battery with 3.0 A charger ⇒ 1.67 hours
  • 3,200 mAh battery with 1.0 A charger ⇒ 3.20 hours

FAQ

Does this include charging losses?

The formula assumes perfect efficiency. Real-world charge times are slightly longer because neither chargers nor batteries are 100% efficient.

Can I use fast chargers?

Yes. Enter the charger's rated output current. If your charger supports multiple modes, use the current that matches your phone's negotiated speed.

How do voltage and wattage ratings factor in?

Current (amps) multiplied by voltage (volts) equals wattage. If you only know wattage, divide by the charger voltage—commonly 5, 9, or 11 V—to estimate current.

Does the starting battery level matter?

The calculation assumes charging from 0% to 100%. For partial top-ups, multiply the full-charge time by the fraction of charge you need to add.

Additional Information

  • Expect real charging to take 10–30% longer due to conversion losses and the trickle phase near 100%.
  • Phones often throttle current as they heat up or approach full capacity, so faster chargers may not sustain peak speed the entire time.
  • Multiply the hours result by 60 to get minutes, or divide by 24 to express it in days for large battery packs.

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