How much does it cost to run an electric heater?
Find out how much your electric heater could cost to run per hour, day, week, month and year. Enter its power rating, your electricity price and how long you use it. You can also adjust the estimated percentage of time the heating element is actually switched on.
Electric Heater Cost Calculator
Enter your heater’s wattage, daily usage and electricity price to estimate its running costs.
Your estimated heater running costs
Important: These figures are estimates. A heater’s actual electricity use can change as its thermostat cycles, power settings change or room conditions vary. The percentage entered above is an assumption, not a measurement. Some heaters also consume a small amount of electricity when their heating element is off.
How Much Does an Electric Heater Cost to Run?
The running cost of an electric heater depends mainly on three things: the heater’s power rating, your electricity price and how long the heating element is actually drawing power.
For example, at an electricity price of 26p per kWh, a heater continuously drawing:
1kW costs about 26p per hour
2kW costs about 52p per hour
3kW costs about 78p per hour
These figures assume the heater is drawing its full rated power continuously. In normal use, a thermostatically controlled heater may switch its heating element on and off as the room reaches the selected temperature, so its average electricity use can be lower.
How is electric heater running cost calculated?
The basic calculation is:
Power in kW × hours used × electricity price per kWh = running cost
For example, a 2,000-watt heater is a 2kW heater. If it draws 2kW continuously for three hours at 26p per kWh:
2kW × 3 hours × £0.26 = £1.56
That means the estimated cost would be £1.56 for three hours of continuous full-power heating.
Does a 2kW heater always use 2kW?
Not necessarily.
A heater rated at 2kW can draw approximately 2kW while its heating element is operating at full power, but thermostatically controlled heaters may cycle the element on and off. Actual electricity consumption therefore depends on factors including the heater’s controls, room temperature, insulation, thermostat setting and operating conditions.
This is why the EnergyCosted heater calculator includes an “Heating element on (% of usage time)” setting. It lets you explore how different assumed operating times could affect the estimated cost.
Frequently Asked Questions
How much does a 2kW heater cost to run for one hour?
At 26p per kWh, a 2kW heater drawing full power continuously would cost approximately 52p for one hour.
How much does a 2kW heater cost to run for eight hours?
At 26p per kWh and continuous full-power operation, the calculation is 2 × 8 × £0.26, giving an estimated cost of £4.16. A thermostatically controlled heater may consume less if its heating element cycles off during that period.
Is a 1kW heater cheaper to run than a 2kW heater?
When both are drawing their full rated power for the same amount of time, a 1kW heater uses half as much electricity as a 2kW heater. However, that alone does not establish which heater will be more economical for a particular room because heating time, thermostat cycling and the amount of heat required also matter.
Can I use my own electricity tariff?
Yes. Enter the price you actually pay per kWh into the calculator rather than relying on the example rate used on this page.
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