Monthly electric heating cost depends on wattage, hours and how much the heater cycles down once the room is warm.
A 2kW heater used four hours a day at full power costs about GBP 59.21 over 30 days at 24.67p/kWh.
This page is best when you are trying to estimate the winter bill effect of regular room heating.
Current rate used: 24.67p/kWh electricity, 5.74p/kWh gas, based on Ofgem price cap, 1 April to 30 June 2026 for Direct Debit customers. Your actual tariff can differ by supplier, region, payment method and meter type.
The full-power column is the clean benchmark. The 65% column is a more realistic starting point for a thermostat-controlled heater in a warmed-up room.
| Heater size | Cost per hour | 4 hours | 7 days at 4h/day | 30 days at 4h/day | 30 days at 65% average output |
|---|---|---|---|---|---|
| 500W | £0.12 | £0.49 | £3.45 | £14.80 | £9.62 |
| 1kW | £0.25 | £0.99 | £6.91 | £29.60 | £19.24 |
| 1.5kW | £0.37 | £1.48 | £10.36 | £44.41 | £28.86 |
| 2kW | £0.49 | £1.97 | £13.82 | £59.21 | £38.49 |
| 2.5kW | £0.62 | £2.47 | £17.27 | £74.01 | £48.11 |
(watts / 1000) x hours x electricity price per kWh
For this page's 2kW example, 4 hours at full output costs £1.97. Used the same way for 30 days, it costs £59.21; at 65% average output it is closer to £38.49.
Short answers to the questions this page is built to solve.
Multiply watts divided by 1000 by hours used, days used and electricity price per kWh. For a 2kW heater used four hours for 30 days at 24.67p/kWh, the monthly cost is about GBP 59.21.
A thermostat-controlled heater may cycle down once the room is warm. Poorly insulated or oversized spaces can keep the heater closer to full power for longer.