How do I work out what my own oil-filled radiator costs?

Multiply its power in kilowatts by the hours you use it and by your unit rate. A 1 kW appliance running for an hour uses 1 kWh, which costs 26p at the Great Britain average. Appliances with a thermostat use less than their rating over an hour.

Does it cost more in some parts of the country?

Slightly. The electricity unit rate under the cap runs from 25.36p a kWh in East Midlands to 27.86p in Merseyside and North Wales, so the same use costs about 10% more in the dearest region. Pick yours in the calculator.

Running costs

How much does it cost to run an oil-filled radiator?

About 53p an hour, at the price cap for 1 October 2026 to 31 December 2026. Used 4 hours a day, that’s about £769 a year.

Common sizes from 1.5 kW to 2.5 kW, with the element on for the whole hour. Once the room is warm the thermostat switches it off for part of each hour.

Verified: 23 October 2026 from Ofgem price cap rates

Work out yours

Your electricity price

Average power while in use

watts

Hours each time

Times a week

An hour

53p

A week

£14.74

A month

£64.05

A year

£769

2,920 kWh a year. Unit rate only: the standing charge is paid whether or not anything is switched on.

An oil-filled radiator is an electric heater: the oil only stores and spreads the heat, it isn’t burned. Every kWh of electricity becomes a kWh of heat, the same as a fan heater, so it costs the same per kWh of heat. What differs is that it warms up slowly and keeps giving off heat after the element switches off.

Its thermostat switches the element on and off to hold the temperature. In a small, well-insulated room it may be on for only part of each hour once the room is warm; in a cold, draughty room it may hardly switch off at all. The cost at full power is the most it can cost.

Ways to spend less

Turn the thermostat down a notch: every hour the element is off costs nothing.
Keep it clear of curtains and furniture so the heat reaches the room.
A timer lets it warm the room before you need it rather than running all evening.

Compared with

Appliance	Typical cost	A year, used as shown
Oil-filled radiator	53p an hour	£769 (4 hours a day)
Electric heater	53p an hour	£576 (3 hours a day)
Electric blanket	4p an hour	£15 (1 hour a day)

At the Great Britain average electricity rate of 26.32p a kWh.

Common questions

How much does it cost to run an oil-filled radiator?: About 53p an hour, at the price cap for 1 October 2026 to 31 December 2026. Used 4 hours a day, that’s about £769 a year. Common sizes from 1.5 kW to 2.5 kW, with the element on for the whole hour. Once the room is warm the thermostat switches it off for part of each hour.
How do I work out what my own oil-filled radiator costs?: Multiply its power in kilowatts by the hours you use it and by your unit rate. A 1 kW appliance running for an hour uses 1 kWh, which costs 26p at the Great Britain average. Appliances with a thermostat use less than their rating over an hour.
Does it cost more in some parts of the country?: Slightly. The electricity unit rate under the cap runs from 25.36p a kWh in East Midlands to 27.86p in Merseyside and North Wales, so the same use costs about 10% more in the dearest region. Pick yours in the calculator.

Other appliances

Add up several appliances in the electricity cost calculator, or see what your own home uses with the smart meter analyser.