Kilowatt-hour

The kilowatthour (symbol: kWh) is a unit for measuring energy. It corresponds to one kilowatt (kW) of power being used over a period of one hour.

The kilowatthour is commonly used for electrical energy, since it may be easier to understand in a practical context than the proper SI unit for energy, the joule, which is a Ws (watt-second). The joule is a comparatively small unit, making numbers quite large.

1 kWh = 3,600,000 joules.