Electric-heater cost calculator
Work out how much it costs to run an electric heater, from its power rating, how long you run it and your electricity price.
Result
Cost per year
Cost per week
How to use this tool
- Check the heater's power setting on its label or manual; the prefilled wattage is an example only.
- Enter how many hours a day and days a week you run it.
- Enter your electricity price per kWh.
- Read the estimated cost per week and per year.
Assumptions
- Assumes the heater runs at full rated power the whole time it's on — a thermostatic heater cycling on and off will cost somewhat less than this in practice.
Technical details: what the fields mean
- Heater power
powerWatts - The selected heater power in watts; use the rating or setting for your specific model.
- Hours per day
hoursPerUse - How many hours a day the heater actually runs.
- Days per week
daysPerWeek - How many days a week you use it.
- Electricity price
pricePerKwh - Your electricity price per kWh — check a recent bill.
Methodology
Energy per week = power (kW) × hours per day × days per week. Weekly cost = energy × your entered electricity price per kWh; the yearly estimate repeats that weekly use for 52 weeks. Costs are displayed in GBP (£), with no live tariff lookup or currency conversion.
Worked example
Illustrative 2000W setting, 4 hours/day, 7 days/week, entered rate 27p/kWh
Inputs: Heater power: 2000 W, Hours per day: 4 hours, Days per week: 7, Electricity price: £0.27/kWh
Result: £15.12/week, £786.24/year. Replace the sample inputs with your heater's rating, use and tariff.
Practical guidance
- A thermostat may cycle the element rather than draw rated power continuously; use a measured average if available, or treat the result as a full-power scenario.
- Compare heating options only when the time period, delivered heat and tariff assumptions are comparable.
Common mistakes
- Assuming a heater's maximum wattage setting is what it always draws — many heaters have adjustable power settings.
- Using electric heaters as a primary whole-home heat source without comparing the running cost to your main heating system.
FAQs
Does this include the electricity standing charge?
No. It estimates only the heater's usage-related cost from power, hours and unit price.
Last reviewed: 2026-10-11
Assumes the selected power is drawn for all entered hours; cycling, thermostat behavior and heat delivered are not modeled.
This tool provides an indicative estimate, based on the assumptions stated above.
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