Appliance Running Cost Calculator
Work out what an appliance costs to run per day, month and year from its wattage, hours of use and your electricity rate.
Last checked 10/11/2026. Sources: Ofgem: Energy price cap unit rates and standing charges; U.S. Department of Energy: Estimating appliance and home electronic energy use.
Guide
How the cost is worked out
Energy in kWh = (watts × hours) ÷ 1,000. Multiply by the days of use, then by your unit rate per kWh.
Example. A 2,000 W heater running 3 hours uses 6 kWh. At the Ofgem price cap rate of 26.32p per kWh that is £1.58.
The electricity rate
The default is the Ofgem price cap unit rate for 1 October to 31 December 2026: 26.32p per kWh (average for people paying by Direct Debit in England, Scotland and Wales). The standing charge (54.83p a day) is a fixed daily cost and is not part of an appliance’s running cost. The cap changes every quarter and your tariff may be different, so use your bill’s unit rate for an exact answer.
Wattage and duty cycle
Check the label for the wattage, remembering that it is often the maximum. Appliances with thermostats or motors, such as fridge-freezers and heaters, only run part of the time, so use the "runs this % of the time" box. The preset wattages are typical figures, not data for your model.
What is not included
Standing charges, other tariffs such as Economy 7, and solar generation are not included.
Common questions
How much does it cost to run an electric heater?
A 2 kW heater running continuously uses 2 kWh an hour, which is about 53p an hour at 26.32p per kWh.
Is the standing charge included?
No. It is charged every day whether you use electricity or not, so it does not change with an appliance.
Do standby appliances cost much?
A device drawing 5 W all year uses about 44 kWh, about £11.50 at the cap rate. Many together can add up.
Why does my fridge use less than its wattage suggests?
Because the compressor cycles on and off. Use the duty cycle box, or the annual kWh on the energy label.
What next?
- Thinking of replacing it? See how long a more efficient one takes to pay for itself. Energy Upgrade Payback Calculator
- Running a heater? Compare it with a heat pump. Electric Heater vs Heat Pump Cost Calculator