Enter an appliance's power in watts, how long it runs and what you pay per unit (kWh), and this works out what it costs you per use, per day and per year. Everything happens in your browser; nothing is saved or sent.
This appliance costs about each time you run it.
Not sure of an appliance's wattage? It is usually printed on a label on the back or base, or in the manual. A plug-in energy monitor measures it directly and pays for itself quickly if you have a few mystery devices. For where the big users hide, see electricity in the home.
An appliance's running cost comes down to three things: how much power it draws in watts, how long it runs, and what you pay per unit of electricity. Divide the watts by 1,000 to get kilowatts, multiply by the hours it runs to get kilowatt-hours (kWh), then multiply by your unit rate. A 2,000W heater for 1 hour uses 2 kWh, which at 26.32p is about 53p. If you only have a kilowatt figure, use the kW to kWh calculator; to turn watts into energy first, see watts to kWh. For the biggest single users, read what uses the most electricity in your home and the full running cost of every appliance. For worked figures on individual appliances, see what it costs to run a dishwasher, an electric hob and an iron.
Common questions
How do I work out an appliance's running cost?
Take the power in watts, divide by 1,000 to get kilowatts, multiply by the hours it runs to get kilowatt-hours, then multiply by your price per kWh. A 2,000W appliance for 1 hour at 26.32p costs about 53p.
How much does it cost to run an appliance for an hour?
Multiply the appliance's power in kilowatts by your unit rate. At the 26.32p cap, a 1kW device costs about 26p an hour, a 2kW one about 53p, and a 3kW one about 79p.
Where do I find an appliance's wattage?
It is usually on a rating label on the back or base of the appliance, or in the manual. A plug-in energy monitor measures it directly, which is handy for anything that switches its power on and off, like a fridge.