Electricity
Battery Capacity Calculator
Turn battery capacity into a watt-hour figure you can actually compare.
Last updated: April 2026
Enter battery capacity and voltage to estimate watt-hours.
Why people need this
Battery listings often push mAh because it looks bigger, while transport rules and many technical comparisons use watt-hours. That mismatch causes confusion all the time.
This calculator fixes that immediately. It is especially useful for power banks, DIY electronics, travel checks and comparing cells with different voltages.
Typical use cases
- power banks
- battery packs
- travel allowance checks
- electronics projects