What is the formula for changing watt consumption to kilowatt hours?

Question

For example, how many kilowatt-hours does a 100 watt bulb use in one hour? Or a 1200 watt electic heater?

Answer 1

Divide Watts by 1000 to get kiloWatts, then multiply by hours to get kiloWatt hours.

100 Watt light bulb divide by 1000 = 0.1 kW times 1 hour = 0.1 kWhr

1200 Watt heater divide by 1000 = 1.2 kW times 1 hour = 1.2 kWhr


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Answer 2

1 watt/hour = .001 kilowatt/hour
100 watt/hour = .1 kilowatt/hour