How much does an oil-filled radiator cost to run?
A large (9 to 11 fin) oil-filled radiator typically costs about 53p to 66p an hour to run, or £2.11 to £2.63 for a 4-hour evening, on the Ofgem price cap for 1 October to 31 December 2026, at full power.
Typical running costs
Typical power from real UK listings, costed at 26.32p per kWh.
| Type | Typical power | Per hour | For a 4-hour evening |
|---|---|---|---|
| Large (9 to 11 fin) | 2000 to 2500W | 53p to 66p | £2.11 to £2.63 |
| Small (5 to 7 fin) | 600 to 1500W | 16p to 39p | 63p to £1.58 |
Heaters use full power only while warming up. Once the room reaches the thermostat setting they cycle on and off, so real costs are usually lower than these full-power figures.
Work out your own
- Per day
- £2.63
- Per week
- £18.42
- Per year
- £958.05
Watts ÷ 1,000 × hours × pence per kWh.
How these figures are worked out
Cost per hour is the power in watts, divided by 1,000, times the unit rate. The rate is the Ofgem price cap, 1 October to 31 December 2026 (direct debit, average, VAT removed). Your own tariff may differ, so check the unit rate on your bill.
Typical power comes from these UK listings: