This battery life calculator estimates how long a battery will last, based on nominal battery capacity and the average current that a load is drawing from it. Battery capacity is typically measured in Amp-hours (Ah) or milliamp-hours (mAh), although Watt-hours (Wh) is occasionally used.

You can convert Watt-hours to Amp-hours by dividing by the battery’s nominal voltage (V) as follows: Ah = Wh / V


Battery Life

Battery Capacity
Device Consumption
Battery Life Formula

Battery Life = Battery Capacity in mAh / Load Current in mAh


*This is an estimated output, based on ideal conditions.