How to use it
- Enter battery capacity in Wh.
- Enter average device power draw in watts.
- Set expected efficiency and calculate runtime.
Battery Runtime Calculator
Estimate ideal device runtime from battery capacity and load.
Runtime is an estimate. Real results depend on battery health, load changes, temperature, and device efficiency.
About the Battery Runtime Calculator
Estimate how long a battery-powered device may run from watt-hour capacity, average load and an efficiency allowance.
Formula
Runtime hours = battery Wh × efficiency ÷ 100 ÷ device watts. Runtime minutes equal hours × 60.
Example
A 60 Wh battery at 90% efficiency supporting a 15 W load gives an ideal estimate of 3.6 hours.
Notes
Capacity declines with age and temperature, while device load varies. Use measured average power and manufacturer runtime data when planning critical usage.