Appliance Energy Use and Cost Calculator
Enter an appliance's wattage, how many hours it runs each day and your electricity rate to see how much energy it uses and what it costs per day, month and year.
How to calculate appliance running cost
- Enter the appliance power in watts (check the label or nameplate).
- Enter how many hours it runs on an average day.
- Enter your electricity rate per kWh from your bill.
- Read the energy use and cost for a day, month and year.
Examples
100 W device for 5 hours a day
100 watts, 5 hours/day, $0.15/kWh
0.5 kWh/day, 182.5 kWh/year, about $27.38 per year
Frequently asked questions
How do I turn watts into kWh?
Multiply watts by hours of use, then divide by 1000. A 100 watt device for 5 hours is 100 x 5 / 1000 = 0.5 kWh.
Where do I find an appliance's wattage?
Look on the rating label or nameplate, often on the back or base. It may be listed in watts, or as volts and amps that multiply to watts.
How are the monthly and yearly costs worked out?
Yearly is daily energy times 365 days. Monthly is the yearly figure divided by 12, so every month is treated the same.
What electricity rate should I use?
Use the per kWh rate on your latest bill. Many homes pay between $0.10 and $0.35 per kWh depending on the region and plan.
Does standby power count?
This tool uses one steady wattage. For devices that idle, add a separate low wattage entry for the standby hours to capture that draw.
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