How do I calculate appliance running costs?
To calculate the running cost of any appliance, multiply its wattage by the number of hours it runs, then divide by 1,000 to get kilowatt-hours (kWh). Multiply by your unit rate in pence to get the cost. For example, a 2,000-watt electric heater running for 3 hours uses 6 kWh. At 24.5p per kWh, that costs £1.47 per session.
Which appliances use the most electricity?
The biggest electricity consumers in most UK homes are electric showers (9kW), electric ovens (2-3kW), tumble dryers (2.5kW), washing machines (2kW), and electric heaters (1-2kW). Small devices like phone chargers and LED bulbs are almost negligible by comparison.