Appliance running-cost calculator

See what an electrical appliance costs to run per hour, day, week and month. The unit rate starts at the Ofgem price cap average of 26.32p per kWh (1 October to 31 December 2026). Change it to match your bill.

All figures stay in your browser; nothing is sent anywhere.

How is it powered?

On the rating plate or in the manual. 1kW = 1,000W.

Default: Ofgem price cap average for Direct Debit customers in England, Scotland and Wales, 1 October to 31 December 2026. Your rate is on your bill and varies by region and tariff.

Estimated cost

How the sum works

Mains appliances: watts ÷ 1,000 = kilowatts. Kilowatts × hours = kilowatt-hours (kWh), the unit on your bill. kWh × unit rate = cost.

Battery tools: battery watt-hours ÷ 1,000 = kWh stored, plus a little extra for charger losses, × unit rate = cost per charge.

Why your real cost may be lower (or higher)

  • Thermostats cycle. A 2kW oil-filled radiator or dehumidifier with a humidistat doesn't draw full power all the time once the room reaches the setting, so these figures are a worst case for the hours you enter.
  • The presets are examples. Wattages vary a lot between models. Use the figure on your appliance's rating plate or in its manual.
  • Standing charges aren't included. You pay those whatever you run.
  • Tariffs differ. Fixed, Economy 7 and prepayment rates can be higher or lower than the cap average. Northern Ireland isn't covered by the Ofgem cap.

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