How much does an electric blanket cost to run?
Very little. A 100W electric blanket costs about 2.6p an hour at the Ofgem cap rate of 26.32p/kWh. Warming the bed for half an hour before you get in costs around 1.3p. Leaving it on all night on full power costs about 21p, and most people use a lower setting than that.
Prices last checked: 26 September 2026 · Source: Ofgem energy price cap, 1 October to 31 December 2026 · Great Britain average, standard variable tariff, paid by Direct Debit
Electric blanket and heated throw costs
Blankets and throws are rated in tens of watts rather than kilowatts. The exact figure is on the controller or the label sewn into the blanket. Dual-control double blankets often list a wattage for each side. The rows below cover the range you will usually see.
| Use | Power | Energy | Cost each time | Per 30 nights |
|---|---|---|---|---|
| Pre-heat bed, 30 min, then off | 100 W | 0.05 kWh | 1.3p | 39p |
| Single blanket, all night on low | 40 W | 0.32 kWh | 8.4p | £2.53 |
| Double blanket, all night on full | 100 W | 0.8 kWh | 21p | £6.32 |
| Heated throw on the sofa, 4 hours | 120 W | 0.48 kWh | 13p | £3.79 |
Blanket vs heating the bedroom
This is where the blanket pays off. Keeping a bedroom warm overnight with a 2kW plug-in heater running only half the time still uses 8 kWh, about £2.11 a night. The blanket on full power uses 0.8 kWh. It heats you, not the air, the walls and the window.
Blankets also work well alongside central heating set lower or timed to go off earlier. Turning the heating off an hour before bed and warming the bed with the blanket shifts the comfort to where you actually are.
Getting the most out of it
- Pre-heat, then switch down or off. Many people only need 20–30 minutes on high before bed.
- Use the timer or auto-off if the controller has one, so it doesn't run all night by accident.
- Put a duvet on top. An over-blanket under a thick duvet holds heat better, so a lower setting feels as warm.
Safety, briefly
Cost is not the only issue. UK fire services regularly remind people to check electric blankets for scorch marks, fraying or damaged wiring, not to fold them when stored, and to replace old ones rather than keep repairing them. Follow the manufacturer's instructions about whether the model can be left on overnight: some are designed for it and some are only for pre-heating.
Common mistakes
- Using the controller's maximum rating for an all-night estimate. On a low setting, the real average is much lower.
- Adding up both sides of a dual-control blanket when only one side is on.
- Treating the blanket as a room heater. It keeps you warm, but a very cold bedroom can still get condensation and mould. Some background heat helps.
Limits of this estimate
Costs use the Ofgem cap average unit rate for Great Britain, Direct Debit. The true average power depends on the setting and the controller design, which manufacturers rarely publish.
Frequently asked questions
Is it cheaper to use an electric blanket or central heating?
For keeping one person warm in bed, the blanket is far cheaper. It uses tens of watts, while heating a room uses thousands. It does not heat the room though, so it works best as a way to run the heating less, not as a full replacement.
How much does an electric blanket cost per week?
Pre-heating for 30 minutes a night at 100W is about 9.2p a week. All night on full power is about £1.47 a week.
Do heated throws use a lot of electricity?
No. A 120W throw on for four hours uses 0.48 kWh, about 13p. That is roughly a quarter of an hour of a 2kW heater.