Browser-local electrical calculator

kWh Calculator

Calculate electrical energy in kilowatt-hours from device power and operating time, with an optional user-entered electricity rate.

Enter values

Result

Enter values and calculate.

Formula and methodology

kWh = power in kW × hours per day × days. Optional estimated cost equals kWh × the rate you enter.

How to use the result

Check that each input uses the intended unit, then compare the displayed result with the assumptions above. Recalculate when the source values or operating conditions change. Do not use an estimate as a substitute for equipment documentation or professional review where safety depends on the result.

Reviewed sources

Method reviewed September 1, 2026. Scheduled review by 2028-08-31.

Related electrical calculators

Browse all Electrical Calculators