Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.

Battery capacity (Ah)

Required number input.

Load current (A)

Required number input.

Compute battery runtime in hours as capacity in ampere-hours divided by load current in amperes. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Runtime (h)

The resulting runtime returned as a number.

• Battery capacity, state of charge, runtime, and aging depend on chemistry, temperature, discharge profile, cutoff voltage, cell balance, charge method, rate capability, self-discharge, and prior history. Nominal amp-hour or watt-hour ratings do not guarantee usable energy under every load.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.

• Capacity From Runtime

  Compute required battery capacity in ampere-hours as load current multiplied by runtime hours.

• Battery Life Calculator

  Estimate battery runtime from rated charge capacity and constant load current: hours = mAh / mA. Real-world derating (Peukert effect, temperature, cutoff voltage) is not modeled.

• Battery Cycle Count Estimate

  Estimate full-equivalent battery cycles from total absolute charge-plus-discharge throughput divided by twice the rated ampere-hour capacity.