Cost to run a space heater
A space heater drawing 2,500 W costs 65.8p for each hour of running at 26.32p/kWh. Used 4 hours a day, 4 days a week, that comes to £45.75 a month.
An hour of running costs
65.8p an hour
That is 2.50 kWh. Used as set, it comes to £45.75 a month and £548.96 a year.
On the label or in the manual.
Standby, thermostats and off-peak use
A thermostat switches it on and off to hold a temperature. 100% if it runs flat out.
Drawn while plugged in and not running.
| Period | Cost | Energy | CO2e |
|---|---|---|---|
| An hour of running | 65.8p | 2.50 kWh | 544 g |
| A day, on average | £1.50 | 5.71 kWh | 1.2 kg |
| A month | £45.75 | 174 kWh | 37.8 kg |
| A year | £548.96 | 2,086 kWh | 453 kg |
How we calculated this
Energy is power multiplied by time: 2,500 W running for an hour uses 2.50 kWh.
The typical figure is the average rating Centre for Sustainable Energy gives for an electric heater. The low figure is the bottom of Virginia Tech’s nameplate range for portable heaters. Real heaters vary by model, so use the number on yours.
The starting use for a space heater, 4 hours a day, 4 days a week, is where the calculator starts, not a measurement of your home: change it to how you use yours. A day is the average across the week, and a month is a twelfth of a 365-day year.
Electricity costs 26.32p/kWh. That is the published figure for the United Kingdom, 1 Oct – 31 Dec 2026, from Ofgem. Average for England, Scotland and Wales, paying by Direct Debit. No VAT on electricity from 1 October 2026 to 31 March 2027.
Standing charges are left out: you pay them whether or not the appliance runs.
Emissions use 0.217 kg CO2e per kWh, the lifecycle intensity of electricity generated in the United Kingdom in 2025, from Ember, via Our World in Data. Lifecycle means building the power stations and supplying their fuel are counted too. It is the grid’s average, not the particular power station an extra appliance brings on.
What drives the cost
A space heater turns every kWh it draws into a kWh of heat, so what it costs comes down to how many hours it is on, not how clever the heater is. At 26.32p/kWh it costs 65.8p an hour at 2,500 W, and a thermostat that switches it off once the room is warm cuts what it actually draws.
Also called: electric heater, fan heater, portable heater, convector heater.
What it costs in the UK, Europe and the US
For a space heater used as typical (4 hours a day, 4 days a week), at each country’s published average electricity price.
| Country | Electricity price | An hour |
|---|---|---|
| United Kingdom | 26.32p/kWh | 65.8p |
| United States (average) | 18.19¢/kWh | 45.5¢ |
| Ireland | €0.4042/kWh | €1.01 |
| Germany | 0,3869 €/kWh | 0,97 € |
| France | 0,2561 €/kWh | 0,64 € |
| Spain | 0,2669 €/kWh | 0,67 € |
| Italy | 0,2966 €/kWh | 0,74 € |
| Netherlands | € 0,2558/kWh | € 0,64 |
Compared with similar appliances
Every electric heater here turns each kWh it uses into a kWh of heat, so at 26.32p/kWh a kWh of heat costs the same whichever you run. A more powerful heater costs more an hour because it gives out more heat, not because it wastes any. Only a heat pump gets more heat from a kWh, because it moves heat in from outside rather than making it.
| Appliance | Typical power | An hour | A year, typical use |
|---|---|---|---|
| Space heater | 2,500 W | 65.8p | £548.96 |
| Oil-filled radiator | 2,000 W | 52.6p | £548.96 |
| Heated towel rail | 450 W | 11.8p | £129.69 |
| Electric blanket | 100 W | 2.63p | £20.59 |
How to spend less on it
- Heat the room you are in, not the house: a heater in a small closed room warms it faster and costs less than the same heater struggling in an open-plan space.
- Use the thermostat or a timer so it stops once the room is warm. A heater that cycles draws full power only part of the time, and the “share of the time at full power” box shows what that saves.
- Keep the heat in: close doors, draw the curtains and block draughts. That matters more than which heater you choose.
- Electricity costs more per kWh than gas, so for heating a whole home a heat pump or gas boiler usually costs less than electric heaters. For one room for a few hours, a heater can still be the cheaper choice.
Questions
How much does a space heater cost to run per hour?
At 26.32p/kWh, a space heater drawing 2,500 W costs 65.8p for every hour of running at full power.
How much does a space heater cost to run a year?
Used 4 hours a day, 4 days a week, it costs about £548.96 a year at 26.32p/kWh, or £45.75 a month.
How many watts does a space heater use?
Most draw between 750 W and 2,500 W while running, and 2,500 W is typical. The rating is on the label or in the manual.
Is a fan heater cheaper to run than an oil-filled radiator?
Not per unit of heat: both turn every kWh into a kWh of heat, so at the same wattage they cost the same to run. A fan heater warms the air quickly and suits short bursts; an oil-filled radiator warms slowly and keeps giving off heat after it switches off.
Does a higher-wattage heater cost more to run?
Yes, by the hour, because it gives out more heat in that hour. A 2,500 W heater costs 65.8p an hour; a heater with half the wattage costs half as much but takes twice as long to give the same heat.
Sources
- How much electricity am I using?, Centre for Sustainable Energy, July 2026. “Electric heater (2500 W)”
- ENERGY SERIES: Estimating Appliance and Home Electronic Energy Use, Virginia Cooperative Extension, Virginia Tech, 26 February 2020. “Heater (portable) = 750–1500”
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