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Electric heater running cost calculator
At the current price cap rate of 26.32p per kWh, a 2 kW heater costs up to 52.6p for every hour it runs flat out. Work out what yours costs per day and per winter.
Defaults from our sources, last updated 2026-10-23.
Estimates only, not financial advice. Results use average UK figures and the assumptions shown. Your real costs depend on your home, tariff, region and installer quotes. Always get several quotes from certified installers and check current tariff rates before deciding. Don't rely on these results alone: see our disclaimer.
How the cost is worked out
Cost = power in kW × hours × price per kWh. A 2,000 W (2 kW) heater running for one hour uses 2 kWh. At 26.32p that is 52.64p. Most heaters have a thermostat that switches the element off once the room is warm, so the "thermostat on-time" field reduces the energy used. 60% is a reasonable starting guess for a heater in a closed room. Use 100% if it never cycles off.
| Heater | Power | Per hour (flat out) | 4 hours/day at 60% | 90 days at that use |
|---|---|---|---|---|
| Small fan heater (low) | 1,000 W | 26.3p | 63p | £57 |
| Oil-filled radiator | 1,500 W | 39.5p | 95p | £85 |
| Convector or fan heater (high) | 2,000 W | 52.6p | 126p | £114 |
| Large oil-filled radiator | 2,500 W | 65.8p | 158p | £142 |
| Halogen heater (2 bars) | 800 W | 21.1p | 51p | £45 |
| Heated airer | 300 W | 7.9p | 19p | £17 |
| Electric blanket | 100 W | 2.6p | 6p | £6 |
At the 1 October to 31 December 2026 price cap average of 26.32p/kWh. Wattages are typical examples, so check the label on your heater.
Is an oil-filled radiator cheaper than a fan heater?
Not per unit of heat. Every plug-in electric heater turns 100% of the electricity it uses into heat, so 1 kWh costs 26.32p whatever the type. Oil-filled radiators feel gentler and keep giving heat after they cycle off, while fan heaters warm a room faster. The real savings come from heating a smaller space, for less time, at a lower temperature.
Electric heater vs central heating
Gas is much cheaper per kWh than electricity: 7.97p against 26.32p under the current cap. Even allowing for a boiler's efficiency of about 88%, gas heat costs roughly 9.1p per kWh. That's about a third of the cost of a plug-in heater. A plug-in heater can still be cheaper overall when you only need to warm one room for a short time, rather than heating the whole house. A heat pump typically makes around 3 kWh of heat per kWh of electricity. Compare running costs in our heat pump vs gas calculator.
Ways to cut the cost
- Use the thermostat and a timer rather than leaving the heater on full.
- Heat the room you're in with the door shut, and draught-proof it.
- If you're on Economy 7, daytime heating is charged at the higher day rate, so storage heaters charged overnight are usually cheaper.
- Heated airers and electric blankets use far less power than room heaters and can replace some heating.
FAQs
How much does a 2kW heater cost to run per hour?
At 26.32p per kWh, up to 52.6p an hour at full power. With the thermostat cycling it off for some of the time, the real cost is often 30–40p an hour.
What is the cheapest electric heater to run?
All plug-in electric heaters are equally efficient per kWh. The cheapest to run is the lowest-wattage heater that keeps you warm enough, used with a thermostat and timer.
Is it cheaper to use an electric heater or central heating?
Per unit of heat, gas central heating is around three times cheaper (9.1p against 26.32p per kWh). A small heater in one room for an hour or two can still cost less than heating the whole house.
How many watts is my heater?
Check the rating label, usually on the back or base. It will show a figure in W or kW. Many heaters have two settings, such as 1,000 W and 2,000 W.
Related calculators
Appliance running cost calculator
Economy 7 calculator
Heat pump vs gas running cost
Standing charges explained
Sources
- Ofgem – Energy price cap unit rates and standing charges (1 Oct–31 Dec 2026)
- Ofgem – Changes to the energy price cap, 1 October to 31 December 2026
- Ofgem – Typical domestic consumption values (2026)
Estimates only, not financial advice. Results use average UK figures and the assumptions shown. Your real costs depend on your home, tariff, region and installer quotes. Always get several quotes from certified installers and check current tariff rates before deciding. Don't rely on these results alone: see our disclaimer.