Electric Blanket Running Cost Calculator
Estimate how much an electric blanket costs to run per night, month and winter season. Add wattage, heat setting, timer hours, tariff and usage days to compare pre-heating a bed with leaving the blanket on for longer.
Blanket and Use Inputs
Estimated Cost
This estimate uses average heat setting as a power factor. Real thermostats may cycle differently.
This result is deliberately small-scale: it shows pennies per night, kWh per night and the season total. That makes it useful for comparing a timed pre-heat with longer use, without treating cost as the only safety factor.
What Changes an Electric Blanket Bill
Power rating
A single underblanket may use much less power than a room heater. Dual controls, larger sizes and throws can use more.
Timer habit
Pre-heating for 30 to 60 minutes costs far less than leaving the blanket on for many hours.
Heat setting
Many blankets cycle on and off after reaching temperature, so the average draw may be below the label wattage.
How to Use the Calculator
Enter the blanket wattage from the label. If a double blanket has two independent sides, the label may show total wattage or wattage per side. Use the number that matches what you switch on. If two people use separate sides, set the count to 2 only when both sides use the wattage entered.
Use average heat setting as a practical power factor. A blanket set to maximum during pre-heat may draw close to its rating. A blanket left on a low setting may cycle and use much less. If you have a plug-in meter, measure one typical night and adjust the percentage until the calculator matches the measured kWh.
Standing charge is optional. Most households pay the daily standing charge regardless of whether a blanket is used, so it should normally be excluded from an appliance running cost. Include it only for a separate supply or a special comparison where fixed supply cost belongs in the decision.
Formula and Method
average watts = blanket watts x heat setting percentage x number of blankets
kWh per night = average watts / 1000 x hours per night
cost per night = kWh per night x electricity unit rate
weekly cost = cost per night x nights used per week
30-night cost = cost per night x 30
season cost = cost per night x season days used + included standing charge
The display rounds money to the nearest penny. Very low nightly costs may still show as a few pence, so compare monthly and season totals when deciding whether a habit matters.
Use Pattern Comparison
| Pattern | Typical input | Cost effect | Safety note |
|---|---|---|---|
| Pre-heat only | 0.5 to 1 hour, high setting. | Usually very low cost. | Switch off before sleep if the product instructions say so. |
| Low overnight setting | 6 to 8 hours, low setting. | Still often modest, but higher than pre-heat. | Use only blankets designed for overnight use. |
| Heated throw on sofa | 1 to 4 hours, medium setting. | Can be cheaper than heating a whole room for one person. | Do not fold tightly while on, and follow washing and storage guidance. |
| Two-sided blanket | Two sides or two items. | Roughly doubles cost if both sides run at the same setting. | Each controller may have different timer behaviour. |
Safety and Suitability Checks
- Read the label: Some blankets are for pre-heating only, while others can be used overnight.
- Check age and condition: Replace damaged blankets, cracked controls, exposed wires or items with scorch marks.
- Avoid unsafe users: Babies, people unable to respond to heat, and some medical situations may make use unsuitable. Ask a health professional where risk is present.
- Store correctly: Do not fold sharply under heavy items. Follow the maker’s washing and drying guidance.
- Register the product: Product registration can help with safety notices and recalls.
Worked Example
A 100 W blanket is used for two hours at an average 60% setting. Average power is 60 W, so nightly use is 0.12 kWh. At 24.67p per kWh, the cost is about 3p per night. Used every night for 120 cold days, that is about £3.55, excluding standing charge.
If the same blanket is left on for eight hours at 40%, nightly use is 0.32 kWh, or about 8p per night. The cost is still modest compared with many room heaters, but suitability and product instructions matter more than saving a few pence.
When the Small Number Still Matters
An electric blanket often costs only pennies per night, so the best use of the result is comparison rather than alarm. Compare pre-heating the bed with running a room heater for the same period, or compare one heated side with two heated sides. The calculator also helps households plan winter routines where several low-power items are used every evening.
Cost should sit behind safety and personal needs. People with reduced sensation, some medical conditions, limited mobility or difficulty using controls should follow medical and product guidance before using heated bedding. Check the cable, controller and fabric regularly, and stop using the product if there are burn marks, exposed wires, overheating signs or damage after washing.
FAQ
Is an electric blanket cheaper than a heater?
Often, because it heats a bed or person rather than a whole room. It is not a substitute where the room must be kept warm for health or damp reasons.
Should I include standing charge?
Usually no. The standing charge is paid for the electricity supply even when the blanket is off.
Can I use this for a heated throw?
Yes. Enter the throw wattage, hours, setting and count.
Can I leave an electric blanket on all night?
Only if the manufacturer says that model is suitable for overnight use. Follow the timer, controller and bedding instructions.
Why does the setting percentage matter?
Many blankets do not draw full power once warm. The percentage gives a practical average when you do not have plug-in meter data.
Sources
- Ofgem (2026) ‘Energy price cap unit rates and standing charges‘. Office of Gas and Electricity Markets.
- Electrical Safety First (2026) ‘Electric blanket safety‘. Electrical Safety First.
- Energy Saving Trust (2026) ‘Heating your home‘. Energy Saving Trust.