One kilowatt-hour is the electrical energy consumed by an electrical appliance in one hour of power 1 kilowatt when it is used for 1 hour.

1 kilowatt hour or 1 kwh

= 1 kilowatt X 1 hour

= 1000 watt X 1 hour

= 1000 joule per second x (60 x 60) seconds

= 3.6 into 10^{6 }J