Energy Units Converter

Convert energy values across common electrical and thermal units, with an optional electricity-cost estimate.

From

Value

1 Kilowatt-hour (kWh) = 3600000 Joule (J)

Energy is measured in kWh. Power (kW) is a rate and is not the same unit. Enter a tariff per kWh to see an estimate for the amount above.

Tariff per kWh

Enter a tariff to see an estimate.

Frequently asked questions

What is the difference between kW and kWh?: kW is power — a rate of energy use. kWh is energy — power multiplied by time. A 1 kW device running for 1 hour uses 1 kWh of energy.
How is the cost estimate calculated?: The cost estimate multiplies the energy in kWh by the tariff you enter. It does not model taxes, fixed charges, or tiered pricing.
Which calorie definition is used?: The thermochemical calorie: 1 cal = 4.184 J. Kilocalorie (kcal, also called a food Calorie) is 4,184 J.