How much does an electric heater cost to run?

A plug-in electric heater, whether a fan heater, oil-filled radiator or convector, turns electricity straight into heat, so a 2 kilowatt heater costs 2 units an hour at full power. That makes it one of the dearest ways to heat a room for any length of time, though it's fine for warming one room briefly.

How we work it out

A typical electric heater uses about 4kWh for 2kw for two hours, taking around 2 hours. Electricity on a standard variable tariff costs about 26p a unit across Great Britain at the moment (it varies a little by region), so one run comes to about £1.05. Your own model may use more or less: the energy label, or a plug-in energy monitor, will tell you.

If you're on a tariff where the price changes through the day, such as Agile Octopus, Economy 7 or an electric car tariff, the same run can cost much less at the right time. The Cheap Watts tool finds that time for you on your own tariff.

How to spend less

• Heat the person, not the room: an electric blanket or heated throw costs a fraction as much.
• Use the thermostat so it cycles off once the room is warm, rather than running flat out.
• Shut the door of the room you're heating.
• For hours at a time, gas central heating usually works out cheaper per unit of heat.

A cheaper option

An electric blanket keeps you warm for about 5% of the cost of running a heater. See what a electric blanket costs to run.