Electric heating cost per month in the UK

Compare heater wattage, daily runtime and thermostat activity using a current official electricity-rate reference—or replace it with the rate from your bill.

Heater size

Five active hours per day.

This table compares four common electrical inputs over 30 days. It assumes the heater draws full power for all five hours.

Heater inputDaily energyMonthly energy30-day cost

500 W2.5 kWh75 kWh£19.58

1 kW5.0 kWh150 kWh£39.17

1.5 kW7.5 kWh225 kWh£58.75

2 kW10.0 kWh300 kWh£78.33

Thermostat scenarios

A 2 kW heater scheduled for five hours.

“Active share” is the portion of the five-hour window during which the heating element actually draws 2 kW.

Active shareActive time/dayMonthly energy30-day cost

25%1.25 hours75 kWh£19.58

50%2.50 hours150 kWh£39.17

75%3.75 hours225 kWh£58.75

100%5.00 hours300 kWh£78.33

Your heating month

Use your heater and your tariff.

Enter scheduled hours and use the active-runtime percentage to represent thermostat cycling.

Your reading

Planning range · based on your inputs

Estimated monthly cost£39.60

Likely planning range £35.64–£43.56

Per day£1.30

Per active hour£0.26

Per year£475.20

Energy / month151.7 kWh

FormulakW × runtime × tariff

Month52 weeks ÷ 12

Data qualitySelf-entered estimate

Rate and evidence

Based on a current official reference.

The examples use Ofgem default tariff cap for Great Britain: GBP 0.2611/kWh, effective 2026-07-01 to 2026-09-30.

The Ofgem cap is an average reference for eligible default tariffs in Great Britain. Your region, payment method, meter and contract may produce a different unit rate.

Confidence A 99/10026.11p per kWh

The standing charge is excluded because running the heater does not add another daily standing charge.

Source: Ofgem price-cap unit rates and standing charges ↗

Calculation

Make active time explicit.

Monthly cost = kW × scheduled hours × active share × days × unit rate

Do not add the household standing charge to the heater. It is payable regardless of whether this one appliance runs.

Interpretation

Wattage alone does not predict the month.

Insulation and draughtsLower heat loss can reduce the time the thermostat keeps the element active.

Heating one roomA portable heater is not directly comparable with whole-home heating unless comfort and heated area are matched.

Heat pumpsThey move heat rather than producing it only through resistance, so use a separate efficiency model.