What is a kWh?
kWh measure energy in hours, for example, 1 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.*
If you would like to find out how much a kWh costs you can read the Ofgem price cap webpage. The price per kWh changes as per every price cap and there is a difference between the cost of electricity per kWh and gas per kWh.
Knowing about kWh’s helps you:
Track your usage: Understand how much electricity different appliances use.
Save money: Identify ways to reduce your electricity consumption and lower your bills.
Be more environmentally friendly: Use energy more efficiently and reduce your carbon footprint.
kWh are only one part of the way we calculate your bill. Read more information on how your bill is calculated or if you’re looking for ways to reduce the amount of energy you use, read our energy efficiency webpage.
* Figures from Ofgem
Last updated: 14 April 2026