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.

Full Charge Capacity (Ah) (Ah)

Required number input.

State Of Charge (%) (%)

Required number input.

Calculate remaining battery charge in ampere-hours from measured full-charge capacity and state of charge percentage. 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]

Remaining Capacity (Ah) (Ah)

The resulting remaining capacity (ah) 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.

• Battery State Of Health

  Calculate battery state of health as measured full-charge capacity divided by rated new capacity, expressed as a percentage; values over 100% can be valid measurements.

• State Of Charge %

  Compute the state of charge of a battery from remaining and full capacity.

• Battery Cycle Count Estimate

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