What is a kilowatt hour (kWh)?
What does kWh mean?
A kWh is a way of measuring energy use. It stands for kilowatt hour.
One kWh is the energy used by a 1,000-watt appliance running for one hour.
Different appliances consume energy at varying rates – 1 kWh is enough to power a 100-watt lightbulb for 10 hours, but a fridge-freezer is expected to use 1 kWh within 26 hours.1
How much does a kWh cost?
If you want to know what a kWh costs, you can check the Ofgem price cap. The price per kWh can change when the price cap is reviewed. The cost also differs between electricity and gas.
Why understanding kWh can help
see how much energy you use
compare how much energy different appliances use
find ways to use less energy and cut costs
make more informed choices about your energy use
More help with your bill
A kWh is only one part of your bill. You can also read more about how your bill is worked out and ways to use less energy.
1
Figures from Ofgem
Last updated: 27 May 2026