"Is it cheaper to use a heated blanket than put the heating on?" is one of the most common winter money questions in the UK. The honest answer is that it depends on your tariff, your home and how you live. The good news is that you can work it out yourself in a couple of minutes, without trusting anyone's headline claim. This article shows you how.
The one formula you need
Every electrical appliance has a power rating in watts (W), printed on the label, the plug-in adaptor or the listing. To find what it costs to run:
Cost per hour = (watts ÷ 1,000) × your electricity unit rate
Your unit rate is on your bill or energy app, in pence per kilowatt-hour (kWh). One kWh is 1,000 watts running for one hour.
The examples below use an illustrative rate of 25p per kWh to keep the sums easy. That is an example, not a quote. Swap in your own rate; the current price cap level is published by Ofgem and changes every three months.
Worked examples (at an example rate of 25p/kWh)
- Heated throw rated 100W on full power: 0.1 kWh × 25p = about 2.5p an hour. Most throws have lower settings that use less, and many cycle on and off once warm.
- Heated blanket or seat pad rated 60W: 0.06 × 25p = about 1.5p an hour.
- Oil-filled radiator rated 1,500W running flat out: 1.5 × 25p = about 37.5p an hour. Once the room is warm the thermostat cuts in and out, so real use is often lower, but you're still in the tens of pence.
- Fan or ceramic heater at 2,000W: 2 × 25p = about 50p an hour on full.
These are maximum figures; check the actual wattage of the product you're considering, as it varies a lot.
Why the gap is so big
A heated throw only has to warm you and the small pocket of air under the fabric. A room heater has to warm all the air in the room, and keep replacing heat lost through windows, walls and draughts. That's why a throw rated at around a hundred watts can feel as comforting as a heater rated at more than a thousand, if you're sitting still under it.
The trade-off is obvious: a throw doesn't warm the room. If you're moving around, have guests, or need the air temperature up for health reasons, a throw isn't a replacement for heating.
What about gas central heating?
Gas central heating is harder to cost per hour because the boiler doesn't run at a fixed rate, and it heats the whole home rather than one spot. But two points generally hold:
- Gas usually costs less per kWh than electricity, often by a large margin. So for heating a whole home, a working gas boiler is normally cheaper per unit of heat than plug-in electric heaters.
- Central heating heats everything, including rooms you aren't using, unless you've turned those radiators down.
So the useful comparison is rarely "throw versus central heating" for the whole house. It's usually: "Can I keep the heating lower or off for the hours I'm sitting still in one room, and use a throw instead?" For a lot of people working from home or watching TV in the evening, the answer is yes.
To estimate your own heating cost, look at your smart meter's in-home display or app on a cold day with the heating on and compare it with a mild day with it off. That gives you a real figure for your home.
When an electric heater makes sense
- Short bursts in one room: warming a small home office for an hour or two, where firing up the whole system would heat empty rooms.
- All-electric homes where a modern panel heater with a good thermostat and timer may be the main heat source anyway.
- Taking the chill off a bathroom or bedroom briefly.
It makes less sense as all-day heating for a home on a standard electricity tariff, where costs add up fast. Our home heaters guide explains the different heater types, and our heater safety article covers what to check before you buy.
What to look for in a heated throw or blanket
- Multiple heat settings and an auto-off timer. Many switch off after a few hours for safety.
- Overheat protection and a detachable controller so the fabric can be washed.
- Clear washing instructions. Many are machine washable at low temperature once the controller is removed; check before you buy.
- Wattage stated on the listing. If a seller won't tell you the power rating, choose another listing.
Follow the manufacturer's safety instructions. Don't use a heated throw folded up, with pins, or with a damaged cable, and check whether a product is suitable for use in bed or only on a sofa. Heated products are generally not recommended for babies, young children or anyone who can't feel heat or switch the product off themselves.
A quick decision guide
- Sitting still for hours in one room? Try a heated throw or seat pad first.
- Need the whole home warm? Use central heating efficiently, with TRVs and a timer.
- One small room for a short time? A plug-in heater can be reasonable; cost it with the formula above.
- Unsure? Check your smart meter display while each option is on. Real data beats any rule of thumb.
For more practical ideas, see how to cut heating costs in a UK flat and our warmth without the bill guide.