How much does it cost to run an electric heater?

Electric heaters do not carry an energy rating label, so the cost comes from the power rating on the appliance and how long it runs: watts × hours ÷ 1,000 = kWh, × your electricity price. The defaults are typical; change them to the rating plate on yours.

Where to find the numbers

Fan heaters, convector heaters and panel heaters are almost all 1,000 W to 2,400 W; the figure is on the rating plate and usually on the box. Your electricity price is the unit rate on your bill (p/kWh).

What the figure is based on

Every electric resistance heater turns electricity into heat at the same rate, so a 2 kW fan heater and a 2 kW oil-filled radiator cost the same per hour at full power. What differs is how the thermostat cycles and how the heat is distributed.

Heating-season use only; days a year defaults to about four months.

What changes the cost

• Every resistance heater is 100% efficient at turning electricity into heat, so the rating and hours running decide the cost, not the type.
• Thermostat and setting: a fan heater on half power draws half the rating; without a thermostat it draws full power all the time.
• Room size and insulation decide how long it has to run to hold temperature.
• A heat pump (reverse-cycle air conditioner) delivers three to four times the heat per kWh of any electric heater.

For a specific model or any other appliance, use the electricity cost calculator.