The short answer
Between 1p and 4p an hour. A 60 W single costs 1.6p an hour (13p a night), a 120 W double 3.2p (25p a night) and a 150 W king or heated throw 3.9p (32p a night), all at full power at the current Ofgem cap. With the thermostat cycling, a typical night is less. A whole winter of nightly use on a double blanket is roughly £35–£40 at the very most.
60 W single, per hour
120 W double, per hour
120 W, 8-hour night
120 W, 30 nights
Cost per hour and per night by wattage
| Blanket power | Per hour | Per 8-h night | 30 nights | Nov–Feb (120 nights) |
|---|---|---|---|---|
| 40 W | 1.1p | 8.4p | £2.53 | £10.11 |
| 60 W | 1.6p | 12.6p | £3.79 | £15.16 |
| 100 W | 2.6p | 21.1p | £6.32 | £25.27 |
| 120 W | 3.2p | 25.3p | £7.58 | £30.32 |
| 150 W | 3.9p | 31.6p | £9.48 | £37.90 |
| 160 W | 4.2p | 33.7p | £10.11 | £40.43 |
All figures assume the blanket is at full power for the whole period. Thermostatic blankets cycle off once the bed is warm, and most people turn the setting down after the first half hour, so real consumption is typically a third to a half of the table.
Why makers say '1p an hour'
Silentnight, Dreamland and others quote around 1p an hour. That figure assumes a lower average draw than the rated wattage — a thermostat-controlled blanket at a mid setting may average 30–50 W — and sometimes an older, cheaper tariff. Our figures use the rated maximum and today's cap, so they are a ceiling, not an average. Both are honest; just know which one you are reading.
Blanket vs room heater vs central heating for one person
For an evening on the sofa: a 120 W throw costs about 13p for four hours; a 1.5 kW fan heater £1.58; a 2 kW heater £2.11. Overnight in bed: a 120 W under-blanket about 25p; a 600 W oil radiator on low £1.26; a 2 kW heater £4.21. If only one or two people need to be warm, the blanket wins every time. Heating the room still makes sense when several people share it, or when the house must be kept above about 16 °C to avoid damp.
See our electric heater guide for the running costs of individual heaters.
Safety and when to replace
UK fire services consistently flag old and damaged electric blankets. Buy a model with overheat protection and an auto-off timer, store it flat or loosely rolled (never folded tightly), keep it dry, and replace it after around ten years or at the first sign of scorching, a frayed cord or a controller that runs hot. Do not use an under-blanket on a memory-foam or adjustable mattress unless the manufacturer says you can.
Running cost of the blankets we recommend
| Product | per hour | per 8-hour night | per month |
|---|---|---|---|
| Silentnight Comfort Control electric under-blanket, double (135 × 120 cm) | 3.2p | 25.3p | £7.58 |
| Silentnight Dual Control electric blanket, double (137 × 150 cm) | 3.2p | 25.3p | £7.58 |
| Homefront fitted electric blanket, king size, dual control (152 × 203 cm) | 3.9p | 31.6p | £9.48 |
| Slumberdown Luxury electric blanket, double, 9 heat settings | 3.2p | 25.3p | £7.58 |
| Morphy Richards EverCosy electric under-blanket, double (150 × 122 cm) | 3.2p | 25.7p | £7.71 |
| Wärmer fully fitted electric blanket, double, dual control | 3.2p | 25.3p | £7.58 |
| Mia&Coco heated throw, flannel and sherpa, 120 × 160 cm | 3.2p | 25.3p | £7.58 |
| Silentnight Comfort Control heated throw, 120 × 160 cm | 3.4p | 27.4p | £8.21 |
| Dreamcatcher heated throw, 9 settings, 12-hour timer, 160 × 120 cm | 3.2p | 25.3p | £7.58 |
| Dreamland Snuggle Up electric throw, velvet plush, 6 settings | 3.9p | 31.6p | £9.48 |
| Dreamland Hunker Down electric blanket, double, Scandi sherpa | 3.9p | 31.6p | £9.48 |
Your own numbers
per hour
per day
per month (30 days)
Frequently asked questions
Does a dual-control blanket cost twice as much to run?
No. The wattage stated is for the whole blanket; two controllers simply split it across the two halves. A 120 W dual-control double costs the same 3.2p an hour as a 120 W single-control double at full power.
Is it cheaper to pre-heat the bed and switch off, or leave the blanket on?
Pre-heating for 30 minutes on high then switching off costs about 1.6p for a 120 W blanket and keeps the bed warm for a while; leaving it on low with the thermostat might average 40–60 W all night, around 8–13p. Both are cheap; choose by comfort.
How much does a heated throw cost to run?
Most are 100–160 W, so 2.6p–4.2p an hour at 26.32p/kWh. A four-hour evening is 11p–17p.
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