Appliance Energy Cost Calculator
Find out exactly how much any appliance costs to run per day, month and year at the current UK electricity rate. Pick a common appliance or enter your own wattage. Updated with the latest Ofgem price cap rate.
Last updated: April 2026
How appliance energy costs are calculated
The cost to run any electrical appliance depends on three things: its power rating in watts, how many hours you use it, and the price you pay per unit of electricity (measured in kilowatt hours or kWh). The formula is straightforward: multiply the wattage by the hours of use, divide by 1,000 to convert to kWh, then multiply by your electricity rate in pence per kWh.
Understanding watts and kilowatt hours
Watts measure how much power an appliance draws at any moment. A 2,000W electric heater uses twice the energy of a 1,000W one in the same time. A kilowatt hour (kWh) is one kilowatt of power used for one hour. So a 2,000W heater running for one hour uses 2 kWh. At the current Ofgem cap rate of 24.67p per kWh, that costs about 49p per hour.
The Ofgem price cap
The Ofgem energy price cap sets the maximum rate suppliers can charge per unit of electricity on standard variable tariffs. From April 2026 this is 24.67p/kWh including VAT. Your actual rate may differ if you are on a fixed deal or prepayment meter. Check your latest bill or tariff letter for your exact rate and enter it above for the most accurate results.
What your results mean
Small wattage differences add up significantly over a year. Switching from a 60W incandescent bulb to a 7W LED saves about £13 per year per bulb if used for 6 hours a day. Appliances on standby typically draw 1-5W, which seems negligible but across 20+ devices can add £30 to £80 per year to your electricity bill.