Appliance Energy Cost Calculator (Free, DOE Method)

How much does it cost to run your space heater, TV or dryer? Pick an appliance (or type the watts from its label), enter how long you use it and your electricity price: the calculator shows the energy used and the cost per day, month and year, using the method from the U.S. Department of Energy.

Key Takeaways

Energy use = watts × hours of use ÷ 1,000, in kilowatt-hours (kWh); multiply by your price per kWh to get the cost (DOE Energy Saver).
Devices that heat or cool (space heaters, dryers, air conditioners) use the most power by far.
Electricity prices vary a lot by state: check yours in the EIA table of average retail prices or on your bill.
The wattage on the label is a maximum: real use is often lower, so treat the result as an upper estimate.

Calculate the Running Cost

Appliance

Power (watts) Hours a day Days a month Price (cents per kWh)

How the Calculation Works

The Department of Energy’s Energy Saver guide estimates appliance energy use the same way: multiply the wattage by the hours used per day, divide by 1,000 to get kilowatt-hours, then multiply by the price you pay per kilowatt-hour. The wattage is usually printed on a label at the back or bottom of the device or in its manual. The typical values in the list above are rough starting points: replace them with your own device’s figure.

For a more exact number, a plug-in electricity usage monitor measures what a device really draws, including standby power when it is “off”.

Ways to Cut the Cost

Replace the biggest users first: an old space heater, dryer or air conditioner costs far more than lights or chargers.
When you buy a new appliance, compare ENERGY STAR certified models, which use less energy than standard ones.
Switch remaining incandescent bulbs to LEDs and unplug devices that stay on standby all day.
Seal drafts and add insulation before buying a bigger heater or air conditioner.

Frequently Asked Questions

How do I find my electricity price?

Divide the energy charge on your bill by the kWh used that month, or check your state’s average in the EIA table. The default of 17 cents is only a round starting point.