Electricity Cost Calculator
Find out what an appliance costs to run per day, month and year from its wattage and your electricity price.
The label wattage is the maximum. Fridges, heaters and other cycling appliances draw full power only part of the time, so measure with a plug-in energy meter for the most accurate figure.
About this tool
Enter the appliance wattage, how many hours a day you use it and your price per kWh. The calculator converts watts to kilowatt-hours and shows the running cost per day, month and year — in any currency.
Frequently asked questions
Multiply the wattage by the hours of use and divide by 1,000 to get kilowatt-hours (kWh), then multiply by your price per kWh. A 100 W device used 5 hours a day uses 0.5 kWh — 15 cents a day at $0.30/kWh.
Look for the rating label on the back or bottom of the appliance or charger, or in the manual. If only amps are given, multiply amps by your mains voltage (e.g. 230 V or 120 V) to estimate watts.
The label shows maximum power. Fridges, freezers, heaters and air conditioners switch on and off with a thermostat, so their average draw is lower. A plug-in energy meter measures actual use.
A kilowatt-hour is 1,000 watts used for one hour — for example a 2,000 W kettle running for 30 minutes. Electricity bills charge per kWh.
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