How Much Does a 2kW Heater Cost Per Hour?
At an electricity price of 26.32p per kWh, a 2kW electric heater costs:
2 × 26.32p = 52.64p per hour
So if the heater operated continuously at its full 2kW output:
| Usage | Approximate cost |
|---|---|
| 30 minutes | 26p |
| 1 hour | 53p |
| 2 hours | £1.05 |
| 4 hours | £2.11 |
| 8 hours | £4.21 |
| 4 hours/day for 30 days | £63.17 |
| 8 hours/day for 30 days | £126.34 |
These calculations use Ofgem’s average electricity unit rate for Direct Debit customers from 1 October to 31 December 2026. Actual tariffs vary by household and region.
How to Calculate Any Electric Heater
Use:
Heater power in kW × electricity rate × hours
So for a 1.5kW heater:
1.5 × £0.2632 = 39.48p per hour
For a 1kW heater:
1 × £0.2632 = 26.32p per hour
For a 500W heater:
0.5 × £0.2632 = 13.16p per hour
Does a 2kW Heater Always Use 2kW?
No.
The 2kW figure tells you its maximum rated power.
If the heater has a thermostat, it should cycle as the room reaches the selected temperature.
So an appliance rated at 2kW might consume 2kW while actively heating and then consume little or no power through its heating element while the thermostat has it switched off.
That means:
52.64p/hour is the cost of one full hour at maximum 2kW draw — not necessarily what every clock hour will cost.
What About Low-Power Mode?
Many heaters offer more than one heat setting.
For example:
1kW low
2kW high
At 26.32p/kWh:
1kW = 26.32p/hour
2kW = 52.64p/hour
Low mode produces less heat, so it isn’t automatically cheaper for completing the same heating task.
But once a room is comfortable, the lower setting may help maintain temperature without producing excessive heat.
Fan Heater vs Oil-Filled Radiator Running Cost
This is where a common misconception appears.
A 2kW fan heater and a 2kW oil-filled radiator cost the same amount per hour while both are continuously drawing 2kW.
At today’s rate, each costs approximately 52.6p per full-power hour.
The difference is in how the heat is delivered.
A fan heater delivers heat rapidly using forced airflow.
An oil-filled radiator heats more slowly and releases warmth more gradually.
Thermostats and the way you use the appliances can therefore result in different total consumption over a real evening, but electricity at the element is still being charged by the kilowatt-hour.
Internal link: Oil-Filled Radiator vs Fan Heater.
Is a Plug-In Electric Heater Expensive?
Compared with using a fan, dehumidifier or small appliance, yes.
Electric resistance heating uses a lot of power.
However, the correct comparison depends on what you’re trying to heat.
If you only need to heat one small home office for an hour, switching on a 2kW heater might make more sense than heating an entire otherwise empty property.
If you need to heat the whole house for many hours, your main central-heating system may be more appropriate.
Does the Standing Charge Matter?
Not for this calculation.
You pay your electricity standing charge regardless of whether this particular heater is switched on.
When estimating the additional cost caused by the heater, use the electricity unit rate.
Ways to Reduce the Cost
Heat the room, not the outdoors
Close external doors and windows while heating.
Stop draughts
Uncontrolled cold-air leakage increases heat loss.
Use the thermostat
Don’t leave a 2kW heater operating at maximum once the room is already comfortable.
Heat the space you’re using
Portable heaters are most useful for targeted heating.
Close curtains after dark
This can reduce heat loss through windows.
Energy Saving Trust likewise recommends closing curtains and blinds after dark to retain heat.
Electric Heater Safety
Portable heaters need space.
Government fire-safety advice says to keep heaters clear of curtains and furniture and never use them to dry clothes.
It also recommends turning heaters off before going to bed.
Do not place a high-powered portable heater on an unsuitable overloaded extension lead.
Bottom Line
Using the current average electricity rate of 26.32p/kWh:
A 2kW heater costs approximately 52.6p for every hour it continuously operates at full power.
But a thermostatically controlled heater may not draw 2kW for the entire period it is switched on.
So when comparing heaters, look beyond the maximum wattage.
Consider how quickly the heater warms the room, how good its thermostat is and how you actually intend to use it.
