How much does a 2kW heater cost per hour in the UK?
A 2kW heater running at full power for an hour uses 2kWh. Multiply that use by your electricity unit rate; the current reference rate is 26.32p per kWh.
Prepared from existing project material on 24 October 2026. Editorial review: not yet recorded. Live figures use the current record; existing evidence dates are unchanged.
See also: Electric heating cost calculator · Electric heating costs per month · Electric radiator reviews · Economy 7 calculator
Heater costs at the current reference rate
Rate: 26.32p per kWh. Full power; four hours per day; thirty days per month. Standing charges excluded.
| Power | 1 hour | 4 hours/day | 30-day month |
|---|---|---|---|
| 1kW | £0.26 | £1.05 | £31.58 |
| 2kW | £0.53 | £2.11 | £63.17 |
| 3kW | £0.79 | £3.16 | £94.75 |
The rate matters as much as the heater
A heater’s rating tells you its maximum electrical demand, not a fixed price. Two households using the same heater can pay different amounts because their tariffs differ. The worked examples below use the currently effective Ofgem reference rate, resolved from PowerGuardian’s energy-market record. It is a reference for comparison, not a promise that your supplier charges that rate in your region.
Find your own unit rate on the latest electricity bill, shown in pence per kWh. Check whether it includes VAT, and whether you have one rate or different day and night rates. A monthly direct debit is not a unit rate and should not be entered into a heater calculation. The electricity standing charge is separate: running an extra heater normally adds units, not a second daily standing charge.
Worked examples: an hour, a day and a month
The calculation is power in kW multiplied by hours used, then multiplied by the unit rate in pounds per kWh. Divide a pence rate by one hundred before converting it to pounds. The table uses the requested 1kW, 2kW and 3kW ratings, one hour at full power, four hours per day and an illustrative thirty-day month. Those are stated scenarios, not measured household use.
A four-hour day at 2kW uses 8kWh when the element is continuously on. Repeat that same pattern for thirty days to obtain the monthly energy use, then apply the rate. Do not read the monthly column as a typical bill: it represents one heater on the stated schedule. An unavailable current rate leaves the cost awaiting a verified update rather than substituting an old price.
Why thermostats change the actual cost
Most thermostatically controlled heaters stop drawing full power once the target temperature is reached, then cycle to maintain it. Four hours switched on is therefore not necessarily four hours with the heating element energised. The time spent drawing power depends on temperature, heat loss, room size and how the controls work. There is no defensible universal percentage to apply to every home.
Use the thermostat on-time field in the electric heating calculator if you have evidence for that share. Otherwise a full-power example is a useful upper-bound scenario, not an expected bill. A suitable energy meter can show actual kWh for a plug-in appliance, provided its rated load covers the heater. Never connect a high-power heater to an unsuitable smart plug or extension just to obtain a reading.
Does a 1kW heater save more than a 2kW heater?
At full power for the same time, the lower-rated heater uses less electricity. But that does not mean it delivers the same comfort for less money. A smaller heater may need to run longer to meet the heat loss of the room. Compare energy used to maintain a comfortable temperature rather than wattage alone, and do not assume a premium electric radiator creates more heat from each unit of electricity.
Direct electric heaters use electricity to produce heat at the point of use. Their controls, placement and responsiveness can change when and where you use that heat. A heat pump is a different technology, so do not apply this resistance-heater table to its heating output rating. Our electric radiator reviews discuss controls and suitability, while the calculator lets you compare the actual ratings and schedules you are considering.
Off-peak and Economy 7 comparisons
An off-peak calculation needs your actual night rate and the exact hours during which it applies. The current single-rate cap token is not an Economy 7 night rate. We have not substituted an unrelated EV tariff or a guessed off-peak price into this table. Enter the rates from your own tariff in the Economy 7 calculator if you want to compare your overall bill.
A lower overnight price only helps the electricity used during that window. Check whether higher daytime rates and standing charges outweigh that benefit. Storage heaters can charge during a cheap period and release heat later; a portable heater used in the evening cannot simply move its heat to the previous night. Do not schedule unsafe or unattended appliance use merely to obtain a lower rate.
Turn the example into your own plan
Write down the heater’s rating, the rooms and hours you actually need it, and the unit rate on your bill. Start with one realistic day, then choose how many days you expect that pattern in the month. Heating demand changes with the weather, so multiplying a winter day by every day of the year can greatly overstate annual use.
Change one assumption at a time in the calculator: hours, power, tariff or thermostat on-time. That makes the effect of each change visible without presenting savings as guaranteed. Keep sufficient warmth for everyone in the household and address draughts or controls where practical. If costs are unaffordable, use the existing support guidance rather than treating a cold home as a budgeting solution. Compare the resulting kWh with actual meter readings where possible, and keep the scenario separate from other appliances and whole-home heating.