How much does a portable electric heater cost to run?
This worked example uses 2,000 W, 4 hours on each use day and 120 use days per year. Change any of these inputs in the calculator.
960 kWh/year · 8.00 kWh per use day
Electricity-price sensitivity
| Electricity price | Energy/use day | Annual energy | Annual cost |
|---|---|---|---|
| 15p/kWh | 8.00 kWh/day when used | 960 kWh/year | £144/yr |
| 25p/kWh | 8.00 kWh/day when used | 960 kWh/year | £240/yr |
| 35p/kWh | 8.00 kWh/day when used | 960 kWh/year | £336/yr |
Important assumption
A thermostatically controlled heater may not draw 2 kW continuously. This page shows a deliberately simple four-hour/day winter-use scenario.
What changes portable heater electricity use?
Portable resistance heaters convert electricity to room heat efficiently at the point of use, but that does not make them cheap to run. A 2 kW heater draws 2 kWh for every hour it is actively heating. Thermostat cycling can reduce the average, while a cold or poorly insulated room can keep it running for long periods.
Make this estimate more realistic
Estimate active heating time rather than simply the hours the heater is switched on. If a thermostat cycles frequently, a measured average over a typical day is better. For whole-home heating decisions, compare the amount of useful heat required rather than only appliance power.
Electricity prices change, so the 15p, 25p and 35p/kWh rows are sensitivity examples rather than a current-tariff claim. Use the linked calculator with the unit rate shown on your own bill before relying on the annual cost.