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Tools / Energy / Portable Electric Heater Running Cost Calculator

Press Enter to move to the next field. On the last field, Enter moves to the result.

Choose a heater type for a rough estimate, or enter the wattage shown on its label or manual.
W
Average your use across seven days, including days when you do not run the heater.
hours
Enter the price you pay for each kWh of electricity.
p

The Ofgem Great Britain average for July to September 2026 is 26.11p per kWh. Enter your own rate for a more accurate estimate.

Estimated cost per month:
£63.53
Cost per hour
£0.52
Cost per day
£2.09
Cost per week
£14.62
Cost per month
£63.53
Electricity used per month
243.33 kWh

Running a 2,000 W heater for an average of 4 hours a day would cost about £2.09 a day, £14.62 a week and £63.53 a month.

* The results provided by this calculator are estimations only. Actual figures may vary due to differences in rates or usage. View full disclaimer

Calculated by SmartMoneyTools.co.uk

How the running cost is calculated

Convert the heater wattage to kilowatts, multiply it by the average hours used per day, then multiply the resulting kWh by the electricity unit rate.

Example calculation

A 2,000 W heater is 2 kW. Running it for four hours a day uses:

2 kW × 4 hours = 8 kWh a day

The estimated daily cost is:

8 kWh × 26.11p = £2.09 a day

That is about £0.52 per hour, £14.62 per week and £63.53 per month.

The monthly figure is an average based on 365 days divided by 12. Your cost for a calendar month will depend on how many days you use the heater.

This assumes the heater runs at its full wattage for every hour entered. A thermostat may switch the heating element on and off, so your actual electricity use could be lower.

Portable heater types and running costs

Fan heaters, convector heaters, halogen heaters, oil-filled radiators and other portable electric heaters deliver heat in different ways. Most turn electricity directly into heat. Two models with the same wattage cost roughly the same to run while both are drawing full power.

Room size, insulation, draughts, thermostat setting and how you use the heater affect how long it needs to run and therefore the total cost. The estimate covers one portable appliance. It does not compare portable heaters with central heating, storage heaters or heat pumps.

Frequently Asked Questions

Where can I find my heater's wattage?
Check the heater label or manual. The power may be shown in watts (W) or kilowatts (kW). Multiply kilowatts by 1,000 to convert them to watts.
Which electricity unit rate should I use?
Use the price in pence per kilowatt hour (p/kWh) shown on your electricity bill or tariff details. Enter it in the unit rate input. Rates vary by tariff and region, so the figure from your bill gives a more accurate result than the Ofgem Great Britain average.
Does this include my electricity standing charge?
No. The estimate covers only the electricity used by the heater. A standing charge is normally paid regardless of whether you use the heater, so it is not added to the result.
What if I run more than one heater or appliance?
Use the Electricity Cost Calculator to add each portable heater and other appliance separately. Give each one its own wattage and daily running time to see individual running costs and the combined daily, monthly and yearly totals.
Tools / Energy / Portable Electric Heater Running Cost Calculator