Battery Runtime Calculator

Estimate how long your battery can power a device based on battery capacity and current draw.

Runtime (hours) = (mAh ÷ 1000) ÷ Current (A)

Converts battery capacity into Amp-hours and divides by the load current to estimate operating time.

How Battery Run Time Works

Battery run time depends on how much energy is stored in the battery and how fast your device consumes that energy.

Battery capacity is rated in Amp-hours (Ah). When multiplied by voltage, it gives total stored energy in Watt-hours (Wh).

Energy (Wh) = Capacity (Ah) × Voltage (V)

Your device consumes power in watts. Dividing stored energy by load power gives the estimated runtime.

Runtime (hours) = Energy (Wh) ÷ Load Power (W)

Real systems lose some energy due to regulators, wiring, and heat, which is why efficiency must be considered.

Battery Runtime calculator