2kW heater for 5 hours a day
2 kW × 5 h × 100% × 26.32p = 263.2p = £2.63 a day. That is £18.42 a week and £80.06 a month.
Home & lifestyle · Energy costs
Electric heater running cost calculator
At the Ofgem price cap rate of 26.32p per kWh (1 October to 31 December 2026), a 2kW electric heater costs about 52.6p an hour to run, or £2.63 a day for 5 hours.
Enter your heater’s wattage, hours a day, electricity price and thermostat on-time for the cost per hour, day, week and month.
52.64pan hour for a 2kW heater at 26.32p per kWh26.32p an hour for 1kW
Work out your heater’s running cost
Runs in your browser, with no run limit
Running cost
Per hour switched on52.64p
Per day£2.63
Per week£18.42
Per month£80.06
Electricity used per day10 kWh
Saved per month by 1 hour less a day£16.01
2 kW × 5 h × 100% × 26.32p = 263.2p = £2.63 a day
A month is 365 ÷ 12 = 30.42 days; a week is 7 days. The standing charge is not included (see below).
Per hour
How much does an electric heater cost to run per hour?
Cost per hour = power in kW × price per kWh. At 26.32p per kWh, with the heater heating all the time:
| Heater power | Electricity per hour | Cost per hour |
|---|---|---|
| 400W | 0.4 kWh | 10.53p |
| 500W | 0.5 kWh | 13.16p |
| 750W | 0.75 kWh | 19.74p |
| 1,000W | 1 kWh | 26.32p |
| 1,500W | 1.5 kWh | 39.48p |
| 2,000W | 2 kWh | 52.64p |
| 2,500W | 2.5 kWh | 65.80p |
| 3,000W | 3 kWh | 78.96p |
Compare schedules
Monthly cost by wattage and hours a day
Cost per month at 26.32p per kWh with the heater heating all the time it is on. A month is 365 ÷ 12 = 30.42 days.
| Heater power | 1 hour a day | 3 hours a day | 5 hours a day | 8 hours a day |
|---|---|---|---|---|
| 500W | £4.00 | £12.01 | £20.01 | £32.02 |
| 1,000W | £8.01 | £24.02 | £40.03 | £64.05 |
| 1,500W | £12.01 | £36.03 | £60.04 | £96.07 |
| 2,000W | £16.01 | £48.03 | £80.06 | £128.09 |
| 3,000W | £24.02 | £72.05 | £120.09 | £192.14 |
Halving the wattage or the hours halves the cost: a 1kW heater for 8 hours a day costs the same as a 2kW heater for 4 hours.
2kW or 3kW
2kW and 3kW heater running costs
A 3kW fan heater costs 78.96p an hour and a 2kW heater 52.64p an hour at 26.32p per kWh, heating all the time. A 3kW heater warms a room faster, so with a thermostat it may switch off sooner: compare the kWh each one actually uses.
| Heater | Per hour | 1 hour a day | 2 hours a day | 5 hours a day |
|---|---|---|---|---|
| 2kW | 52.64p | £0.53 a day, £16.01 a month | £1.05 a day, £32.02 a month | £2.63 a day, £80.06 a month |
| 3kW | 78.96p | £0.79 a day, £24.02 a month | £1.58 a day, £48.03 a month | £3.95 a day, £120.09 a month |
Oil-filled radiators are usually 2kW or less: see the oil-filled radiator running cost calculator. To compare a heater with an electric blanket, dehumidifier or heated airer, use the appliance running costs calculator.
Step by step
Worked examples
Daily cost = kW × hours a day × on-time × price per kWh. Weekly cost = daily × 7. Monthly cost = daily × 365 ÷ 12.
1.5kW heater for 3 hours a day
1.5 kW × 3 h × 100% × 26.32p = 118.44p = £1.18 a day. That is £8.29 a week and £36.03 a month.
3kW fan heater for 2 hours a day
3 kW × 2 h × 100% × 26.32p = 157.92p = £1.58 a day. That is £11.05 a week and £48.03 a month.
500W heater for 8 hours a day
0.5 kW × 8 h × 100% × 26.32p = 105.28p = £1.05 a day. That is £7.37 a week and £32.02 a month.
Thermostats
Thermostats: why the real cost is often lower
A heater with a thermostat switches its element off once the room reaches the set temperature and back on when it cools, so it draws full power only part of the time it is switched on. For example, a 2kW heater on for 5 hours that is heating 50% of that time uses 5kWh, not 10kWh: £1.32 a day, £9.21 a week and £40.03 a month at 26.32p. How much of the time it heats depends on the room, its insulation, the weather and the setting, so this page does not assume a typical figure. Leave the on-time at 100% for the most a heater can cost, or use a plug-in energy monitor to measure the kWh your heater actually uses.
Heater types
Do fan heaters, convectors and oil-filled radiators cost different amounts?
Not at the same wattage and on-time. Each turns the electricity it uses into heat, so 2kW for 1 hour is 2kWh whichever type it is. They differ in how quickly they heat a room (a fan heater moves warm air quickly; an oil-filled radiator warms up slowly and keeps giving off heat after it switches off) and so in how their thermostats cycle. Compare running costs by wattage and the time each one actually spends heating.
Wattage
How to find your heater’s wattage
Look on the rating plate or sticker (usually on the back or base) or in the manual for a figure in W or kW, for example 2000W or 2kW. Heaters with low and high settings (such as 1kW/2kW) use the lower figure on the low setting, so enter the setting you run it on. 1kW = 1,000W.
Your bill
Standing charges are not included
Your electricity bill also has a daily standing charge: an Ofgem average of 54.83p a day on Direct Debit for October to December 2026. You pay it whether or not the heater is on, so it is left out of appliance running costs. Only the unit rate (pence per kWh) changes with how much you use the heater.
Source
Where the 26.32p figure comes from
26.32p per kWh is Ofgem’s GB average Direct Debit electricity unit rate under the energy price cap for 1 October to 31 December 2026. There is no VAT on electricity from 1 October 2026 to 31 March 2027. The cap rate varies by region and payment method, and fixed, Economy 7 and prepayment tariffs differ, so use the unit rate on your bill if you know it. The next price cap period starts on 1 January 2027. Source: Ofgem, energy price cap unit rates and standing charges.
Helpful answers
Electric heater running cost FAQs.
How much does a 2kW heater cost to run per hour?
About 52.6p an hour at 26.32p per kWh, the Ofgem price cap average for 1 October to 31 December 2026: 2kW for 1 hour uses 2kWh, and 2 × 26.32p = 52.64p. If a thermostat switches it off part of the time, the cost is lower in proportion.
How much does a 3kW heater cost to run per hour?
About 79.0p an hour at 26.32p per kWh: 3kW for 1 hour uses 3kWh, and 3 × 26.32p = 78.96p. Two hours a day costs £1.58 a day, or £48.03 a month. A 3kW heater costs half as much again as a 2kW heater for the same time.
How much does a 1kW heater cost per hour?
About 26.3p an hour at 26.32p per kWh, because a 1kW heater uses 1kWh in an hour of continuous heating.
Is the standing charge included?
No. The daily standing charge (an Ofgem average of 54.83p a day on Direct Debit for October to December 2026) is paid whether or not the heater is on, so it is not part of the heater’s running cost.
Do oil-filled radiators cost less to run?
Not at the same wattage and on-time. Every electric heater turns the electricity it uses into heat, so a 2kW oil-filled radiator, convector or fan heater running for 1 hour uses 2kWh. They differ in how quickly they warm a room and how their thermostats switch on and off, which changes the on-time.
How much does a 2kW heater cost to run per month?
£80.06 a month for 5 hours a day at 26.32p per kWh with the heater on all the time (10kWh a day, £2.63 a day, over 30.42 days). At 50% thermostat on-time it is £40.03.