Which electric heater is cheapest to run?
For the same power and the same time, every plug-in electric heater costs the same to run. What changes the cost is how many watts it draws and for how long.
Uses Ofgem's price cap for 1 October to 31 December 2026. Prices checked 13 November 2026.
Result
An oil-filled radiator (2,000 W) costs 52.6p an hour to run at the price cap rate of 26.32p per kWh.
an hour, to the nearest penny
| A day | £2.11 |
|---|---|
| A week | £14.74 |
| A month | £64.05 |
| A year | £768.54 |
| Electricity used in a year | 2,920 kWh |
That is more electricity than a typical home uses in a year for everything (2,500 kWh).
Show the workings
| Step | Sum | Answer |
|---|---|---|
| Turn watts into kilowatts | 2,000 W ÷ 1,000 | 2 kW |
| Cost of one hour | 2 kWh × 26.32p per kWh | 52.6p |
| Cost of one day's use | 52.6p × 4 hours | £2.11 |
| Cost of one week | £2.11 × 7 days | £14.74 |
| Cost of one year | £14.74 ÷ 7 × 365 days | £768.54 |
What this leaves out or assumes
- The standing charge is left out, because you pay it whether or not you use this appliance.
- A month is one twelfth of a year.
- The appliance draws its full power for the whole time it is on.
Where the figures come from
- Electricity unit rate, price cap, Great Britain average, Direct Debit: 26.32p per kWh. Source: Ofgem: Energy price cap unit rates and standing charges. Checked 13 November 2026.
- Typical yearly electricity use, medium user: 2,500 kWh a year. Source: Ofgem: Review of typical domestic consumption values, decision (Table 1). Checked 13 November 2026.
Typical power for an oil-filled radiator is from Centre for Sustainable Energy: How much electricity am I using?. Yours may differ: check its rating plate.
Why the type matters less than you might think
You pay for electricity by the kilowatt hour. A 2,000 watt fan heater and a 2,000 watt oil-filled radiator running flat out for an hour both use 2 kWh, so both cost 52.6p at the price cap. The label on the box may say "efficient", but the meter only counts kWh.
The type changes how the heat reaches you. A fan heater blows warm air and heats a small room quickly. An oil-filled radiator warms up slowly and keeps giving off heat for a while after it switches off. A radiant or infrared heater warms the people and things in front of it rather than the air. Choosing the one that suits the room can mean running it for less time, and that is where the saving is.
What a heater costs by the hour
At the price cap rate of 26.32p per kWh, running at full power:
| Heater power | An hour | A 4-hour evening |
|---|---|---|
| 500 W (0.5 kW) | 13.2p | 52.6p |
| 1,000 W (1 kW) | 26.3p | £1.05 |
| 1,500 W (1.5 kW) | 39.5p | £1.58 |
| 2,000 W (2 kW) | 52.6p | £2.11 |
| 2,500 W (2.5 kW) | 65.8p | £2.63 |
| 3,000 W (3 kW) | 79p | £3.16 |
A heater with a thermostat switches off once the room reaches the temperature you set, so it costs less than the table once the room is warm. Typical ratings from the Centre for Sustainable Energy are 2,500 W for an electric heater and 2,000 W for an oil-filled radiator.
Ways to spend less
- Use a lower power setting if the heater has one. Half the watts costs half as much an hour.
- Use the thermostat and a timer, so it only runs when you need it.
- Heat the room you are in, with the door closed, rather than the whole house.
Electric heater or gas central heating?
Under the price cap, a kWh of electricity costs 26.32p and a kWh of gas costs 7.97p, so electricity costs 3.3 times as much for each unit. A gas boiler loses some heat up the flue, so the gap in the heat you get is a little smaller than that, but gas is still usually cheaper per unit of heat. An electric heater can still cost less overall if it means you heat one room for an hour instead of the whole house.
Prices: Ofgem: Energy price cap unit rates and standing charges. Typical power ratings: Centre for Sustainable Energy: How much electricity am I using?.