How appliance running costs are worked out
Electricity is sold by the kilowatt-hour (kWh): using 1,000 watts for one hour. To find what an appliance costs, work out how many kWh it uses and multiply by your unit rate:
- kWh = watts ÷ 1,000 × hours used
- Cost = kWh × unit rate
A 2,500 W tumble dryer running for an hour uses 2.5 kWh. At 26.32p per kWh that’s about 66p a load, or around £34 a year at one load a week.
The Ofgem price cap from 1 October 2026
Ofgem sets a cap on the unit rates and standing charges suppliers can charge on standard variable (default) tariffs. From 1 October to 31 December 2026 the average capped electricity price for Direct Debit customers in England, Scotland and Wales is 26.32p per kWh with a standing charge of 54.83p a day. VAT has been removed from electricity bills from 1 October 2026 to 31 March 2027. From 1 July to 30 September 2026 the rates were 26.11p per kWh and 57.19p a day, including 5% VAT.
These are averages. Your rate depends on your region, how you pay and your meter. Fixed tariffs, Economy 7 and prepayment meters can be different, so type in the unit rate from your bill if you know it. Northern Ireland isn’t covered by the Ofgem cap.
Getting an accurate figure
Many appliances don’t run at full power all the time. Heaters, ovens and fridges switch on and off with their thermostat, and a washing machine uses most of its energy heating water at the start of a cycle. For these, the yearly kWh on the energy label (or a plug-in energy monitor) is more accurate than the maximum wattage.
Sources: Ofgem – Energy price cap standing charges and unit rates by region and Ofgem – Energy price cap explained (cap periods, VAT). Last checked 8 October 2026.