Household electricity
Appliance running cost calculator
Compare the cost of running the same appliance for different lengths of time. Use your appliance’s power rating and the unit rate on your electricity bill.
This is not financial advice. The figures are illustrative estimates. Actual results may differ. Read the disclaimer.
Enable JavaScript to explore the calculator. The methodology and frequently asked questions are available below.
How the cost is estimated
Divide watts by 1,000 to get kilowatts. Multiply by the hours and days used each week to estimate weekly kilowatt-hours (kWh). Then multiply by your unit rate. The yearly estimate uses 52 weeks and the average monthly cost is one twelfth of the yearly cost.
How much does a 2 kW electric heater cost to run? At an illustrative rate of 25p per kWh, it costs 50p for one hour or £1 for two hours if it runs at full power throughout.
The example unit rate is illustrative. The calculation assumes constant power and a constant unit rate and excludes standing charges and standby use outside the hours entered.
Common questions
Where do I find the power rating?
Look for a wattage (W) on the appliance label or in the manual. Appliances such as fridges and heaters cycle on and off, so rated power can overestimate typical consumption.
Which rate should I enter?
Use the price per kilowatt-hour in pence, rather than your daily standing charge. The estimate uses the same rate for every hour.