Electricity Cost Calculator

Find out what any appliance or device costs to run. Enter its power in watts, how long you use it and your electricity rate to see the cost per hour, day, month and year.

Appliance
W
Check the label on the appliance or its manual.
¢/kWh
U.S. average: 18.56¢ (EIA, March 2026). Your bill shows your own rate.
Cost per month$66.82
Cost per day
$2.23
Cost per year
$813 (used every day)
Cost per hour
$0.28
Energy per month
360 kWh

What you will need

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How this calculator works

Energy use in kilowatt-hours is watts × hours ÷ 1,000. Multiply by your price per kWh to get the cost, as described in Virginia Cooperative Extension’s guide Estimating Appliance and Home Electronic Energy Use.

The default rate is the U.S. average residential price of 18.56¢ per kWh from the EIA Electric Power Monthly (March 2026). Use the rate on your own bill for a more accurate result.

Appliances with thermostats or compressors — refrigerators, heaters, air conditioners — cycle on and off, so the hours they actually draw full power can be less than the hours they are switched on.

Example: a 1,500 W space heater, 8 hours a day

  1. Energy per day: 1,500 × 8 ÷ 1,000 = 12 kWh.
  2. Per month (30 days): 12 × 30 = 360 kWh.
  3. Cost at 18.56¢/kWh: 360 × $0.1856 = $66.82 a month.

Quick reference

Typical appliance wattages (Virginia Cooperative Extension)
ApplianceTypical watts
Portable heater750 – 1,500 W
Clothes dryer1,800 – 5,000 W
Water heater (40 gal)4,500 – 5,500 W
Dishwasher1,200 – 2,400 W
Microwave oven750 – 1,100 W
Ceiling fan65 – 175 W
Laptop50 W

Tips before you buy

  • A plug-in energy monitor shows the real watts and kWh an appliance uses, including standby power.
  • Heating and cooling are usually the biggest costs; small electronics rarely add more than a few dollars a month.
  • Check our electric bill calculator for the average rate in your state.

Common sizes

Guides

Frequently asked questions

How do I calculate the cost of running an appliance?

Multiply the watts by the hours of use and divide by 1,000 to get kWh, then multiply by your electricity rate. A 1,000 W appliance used for 1 hour uses 1 kWh, which costs about $0.19 at the U.S. average rate.

How much does it cost to run a space heater?

A 1,500 W space heater uses 1.5 kWh per hour, about $0.28 per hour at the U.S. average rate of 18.56¢/kWh, or about $67 a month if it runs 8 hours a day.

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Last updated October 26, 2026