Work out what it costs to run an appliance. Enter its power in watts, how many hours a day you use it and your price per kilowatt-hour, and see the cost per day, month and year.
| Cost per day of use | – |
| Cost per year | – |
| Energy per month | – |
How it works
Energy (kWh) = power in kilowatts × hours used. Watts divided by 1,000 gives kilowatts. Cost is the energy multiplied by your price per kWh, which appears on your electricity bill. Many appliances do not draw full power all the time (a fridge or heater cycles on and off), so use an average if you know it.
Example
A 1,500 W heater used 2 hours a day uses 3 kWh a day. At 0.25 per kWh that costs 0.75 a day, or 22.50 over 30 days.
Frequently asked questions
How do I find an appliance’s wattage?
Look at the label on the appliance or in its manual. If it shows amps and volts, multiply them to get watts.
Does standby power count?
Yes. Many devices use a small amount when they are off. Add it if you want a full picture.
Where do I find my price per kWh?
On your electricity bill or your supplier’s website. Some suppliers have a standing charge as well.
More free tools: Ohm’s law calculator · Unit converter · All free tools
Estimates only. Actual use depends on how the appliance runs.