Electric heater running cost calculator
Most plug-in heaters are 2 kW on full and about 1 kW on low. Enter how long you run it and the unit rate from your bill.
Measuring in feet and inches? Use the US version
Cost per month
91.25 in your currency
- Per hour
- 0.5
- Per day
- 3
- Energy per day
- 12 kWh
- Per winter
- 456.25 (5 months)
How it works
A heater’s power in kilowatts × the hours it runs gives kilowatt-hours (kWh), the unit on your bill. Multiply by your price per kWh to get the cost. A month here is an average month, a year divided by 12. The result is in whatever currency your price is in.
This assumes the heater runs at full power the whole time. One with a thermostat switches off once the room is warm, so if yours does, enter the hours it actually heats.
Example
With heater power 2,000 watts, hours used per day 6 hours, number of heaters 1, price per kWh 0.25, months of use per winter 5 months, the answer is 91.25 in your currency.
Tips before you buy
- Heating just the room you’re in with a portable heater, while the rest of the home is kept cooler, can cost less than heating the whole house. Heating several rooms this way usually costs more than gas central heating or a heat pump.
- Every electric heater, oil-filled, fan or convector, turns all its power into heat. A 2 kW heater costs the same to run whatever its type.
- Plug heaters straight into a wall socket, not an extension lead, and keep them a metre from anything that can burn.
Common questions
How much does a 2 kW heater cost to run per hour?
2 kWh times your price per kWh. At 25p per kWh, that’s 50p an hour, or £3 for six hours.
Is an oil-filled radiator cheaper to run than a fan heater?
Not per kWh: both turn all their power into heat. An oil-filled radiator holds heat longer after its thermostat switches off, which can mean it runs fewer hours.
How much does it cost to run a heater all winter?
A 2 kW heater for 6 hours a day at 25p per kWh is about £91 a month, or about £456 over five months.