At the Ofgem cap rate for 1 October to 31 December 2026, an electric heater rated 2000W costs about £1.58 a use and £189.50 a year when 5 hours a time, once a day.
| Per hour of running | 31.6p |
|---|---|
| Per use | £1.58 |
| Per day | £1.58 |
| Per year | £189.50 (720 kWh, over 120 days of use) |
Calculated at 26.32p per kWh, the capped electricity unit rate for 1 October to 31 December 2026 on a standard variable tariff paid by direct debit. Electricity carries no VAT in that period, so this is the full unit price. The 54.83p daily standing charge is not included, because you pay that whether or not anything is switched on.
Two things worth knowing about that figure. The cap limits the unit rate, not your bill, so using more still costs more. And it is a Great Britain average: the actual capped rate is set per region, so your own rate could move these numbers either way. It is on your bill.
The annual figure assumes 120 days of use a year rather than 365, because electric heater is seasonal. Running it every day of the year would cost £571.81.
Electric heater has a thermostat, so the element or compressor switches off once it reaches temperature and back on when it drifts. The figures above assume it draws full power roughly 60% of the time it is on, which is typical.
This is where most running-cost figures online go wrong. Multiplying 2000W by the hours it is switched on would give £953.01 a year, which is roughly 1.7 times the real figure.
Figures for electric heater run from about 500W to 3000W. Every electric resistance heater is 100% efficient at turning electricity into heat, so a 2kW fan heater, oil filled radiator and halogen heater all produce the same heat for the same money. The differences are in how the heat is delivered and whether a thermostat cycles the element off once the room is warm. A heater with no thermostat runs continuously and costs the most.
Heat the room you are in rather than the house, and use the thermostat rather than the power setting. If you are heating a room for many hours a day through winter, a heat pump delivers roughly three units of heat per unit of electricity, which resistance heating cannot match.
Believing one type of electric heater is cheaper to run than another at the same wattage. They are not, and any claim otherwise is about comfort, not cost.
Annual running cost against the appliances closest to it, on the same assumptions. The ordering surprises people: short bursts of very high wattage usually cost less than something modest left on for hours.
| Appliance | Per year |
|---|---|
| Electric heater | £189.50 |
| Desktop PC | £153.71 |
| Tumble dryer | £144.10 |
| Dishwasher | £121.05 |
| Fridge freezer | £103.75 |
Across a year, an electric heater on these assumptions is about 28.8% of a typical annual electricity bill of £658.00 at these rates.
The figures here use the capped rate. If you are on a fixed tariff, or you want to add several appliances together, put your own unit rate into the energy cost calculator on the homepage.