Electric heater running cost calculator

At 26.32p per kWh, a 2 kW electric heater costs 52.6p an hour on full power. The same heat from a gas boiler costs about 18.8p.

  • By Steven Stewart
  • Checked 20 October 2026
  • Ofgem price cap, October to December 2026
  • 2 sources

Picking one fills in typical figures. Use the wattage on your heater.

watts

Use the setting you run it on, e.g. 1000 W on a 2000 W heater’s low setting.

hours
days
%

With a thermostat, the heater switches off once the room is warm. 100% is the most it can cost.

p per kWh

Storage heaters usually run on a cheaper overnight rate, such as Economy 7.

Cost this winter (26 weeks)£287.41
An hour
39.5p
A day
£1.58
A week
£11.05
A month
£47.90
Same heat from gas, an hour
14.1p

1,500 W heater on for 4 hours a day, 7 days a week, heating 100% of the time, at 26.32p per kWh.

Winter means October to March. Excludes the daily standing charge.

Electric heater costs per hour

At 26.32p per kWh, on full power, compared with the same heat from a gas boiler.

HeaterTypical powerPer hourSame heat from gas
Oil-filled radiator1,500 W39.5p14.1p
Convector heater2,000 W52.6p18.8p
Fan heater2,000 W52.6p18.8p
Panel heater1,000 W26.3p9.4p
Halogen heater1,200 W31.6p11.3p
Storage heater2,500 W65.8p23.4p

How we calculate this

Every electric heater turns electricity into heat at almost 100% efficiency, so the cost depends only on its power, how long it runs and your rate. Types differ in how they spread heat, not in how cheaply they make it.

For comparison, a gas boiler at 85% efficiency makes heat for about 9.4p per kWh at the current cap, against 26.32p for electric.

Cost per hour = (watts ÷ 1,000) × time heating × unit rateCost this winter = cost per week × 26Same heat from gas = kWh × 7.97p ÷ 0.85

Questions people ask

Which electric heater is cheapest to run?

They all cost the same per kWh, because they all turn electricity into heat almost perfectly. The cheapest is the one that heats only the space you need, for the shortest time. A thermostat and a timer help most.

Is it cheaper to use an electric heater or the central heating?

Per unit of heat, gas central heating is cheaper: about 9.4p per kWh against 26.32p. But heating one room with a small heater can cost less than heating the whole house, if you only use that room.

How much does an oil-filled radiator cost per hour?

A 1,500 W oil-filled radiator costs up to 39.5p an hour at the price cap. With its thermostat cutting in and out, the real cost is often lower.

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