What Does It Cost to Run an Electric Heater?
A 2 kW electric heater used for 3 hours a day over 90 days uses 540 kWh, which costs about £142 at the Ofgem price cap rate of 26.32p per kWh. A heat pump giving the same heat at COP 3 would use 180 kWh.
Try your own numbers
Last checked 10/11/2026. Sources: Ofgem: Energy price cap unit rates and standing charges.
What goes into the figure
A 2 kW heater uses 2 kWh for every hour at full power. Three hours a day is 6 kWh, and over 90 days that is 540 kWh. At 26.32p per kWh that costs £142.13.
The rate is the Ofgem price cap unit rate for 1 October to 31 December 2026 (average for Direct Debit customers in England, Scotland and Wales). The cap changes each quarter, and the next change is due on 1 January 2027, so use your own tariff’s unit rate for a firm answer. The standing charge (54.83p a day) is not part of the heater’s cost.
The heat pump column shows what the same heat would cost from a heat pump. A COP of 3 is an editorial assumption: it varies with the model and the outside temperature, so use the rated figure if you have one. A thermostat that switches the heater off when the room is warm will lower the first number too.
Common questions
Is it cheaper than gas?
This tool does not compare gas. The Ofgem gas unit rate for the same period is 7.97p per kWh, but boiler and radiator efficiency also matter.
Does a 2 kW heater always draw 2 kW?
Only when it is on full. With a thermostat it cycles, so the real use is lower.