Everyday Money
Appliance Running Cost Calculator
Enter power, how long it runs, and your unit rate to estimate electricity cost.
How much does an appliance cost to run?
Electricity prices make small wattage differences matter over a year. A tumble dryer, dehumidifier or aquarium heater can cost more to run than its purchase price suggests. This calculator turns wattage (or kWh per cycle) and your unit rate into cost per hour, per day and per year so you can compare appliances before you buy or decide when to run them. Use the rating plate wattage and the unit rate from your bill, not a comparison-site average, for a closer estimate. Standby power is ignored unless you include it in hours. For hot-water habits, see also cost per shower. Figures are illustrative estimates, not an energy-supplier quote. Smart plugs with energy monitoring can validate the estimate after a week of real use. For heat pumps and inverter devices, prefer handbook kWh figures over simple watts × hours because draw varies with load.
Worked example
A 2,000 W heater used 3 hours a day at 28p/kWh: 2 kW × 3 h = 6 kWh/day → £1.68/day, about £613/year. Switching to 1 hour on a timer cuts the estimate to roughly £204/year before you count loft insulation changes. A dishwasher labelled 1.1 kWh per Eco cycle at 28p/kWh costs about 31p per wash; at one wash a day that is roughly £113 a year before rinse aid and salt.
Limits and assumptions
Nameplate wattage is a maximum; thermostats cycle power down. Heat pumps and inverter appliances need handbook kWh figures. Standing charges and Economy 7 night rates are not modelled unless you enter an average blended unit rate.
Frequently asked questions
Where do I find appliance wattage?
On the rating plate, in the manual, or sometimes on the retail listing. Convert kW to watts by multiplying by 1,000.
Should I use peak or off-peak unit rates?
Use the rate that applies when you run the appliance, or a blended average if usage spans both.
How accurate is the yearly estimate?
It assumes steady hours and price. Seasonal use and tariff changes will move the real bill.
Can I compare gas and electric?
Convert both to kWh cost using your tariffs. This page is built for electrical wattage inputs.
What about washing machines per cycle?
Prefer the handbook kWh per cycle if listed; otherwise estimate hours × watts. Pair with cost per use for purchase-plus-running totals.