Electricity Cost Calculator
Find out what a space heater, TV, gaming PC or fridge really costs to run. Pick an appliance or enter its wattage, set how long it runs and your electricity rate, and see the cost per day, month and year.
Cost per month
How to calculate electricity cost
- Pick an appliance from the list, or enter the wattage from its label or manual.
- Enter how many hours a day and how many days a month you use it.
- Enter your electricity rate from your bill (the total cost divided by kWh used gives your all-in rate). The US average is around 17 cents per kWh.
How appliance energy costs work
Energy use is power multiplied by time. A 1,500-watt space heater running for one hour uses 1.5 kilowatt-hours (kWh). At 17 cents per kWh, that hour costs about 25 cents; run it 5 hours a day for a month and it adds roughly $38 to your bill. The formula is simply watts × hours ÷ 1,000 × price per kWh.
Label wattage is a maximum. Appliances that cycle on and off, like refrigerators, air conditioners and heaters with thermostats, use less than their rated power over a day. The refrigerator preset uses a typical average draw rather than its peak. For exact numbers, a plug-in energy monitor measures real usage.
The biggest savings usually come from heating, cooling, water heating and dryers. Swapping incandescent bulbs for LEDs cuts lighting costs by about 85%, and unplugging or using smart strips for devices with standby power trims a few more dollars a month.
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Frequently asked questions
How do I find my electricity rate?
Divide your bill's total (before taxes if you prefer) by the kWh used that month. Rates in the US range from about 11 to over 40 cents per kWh by state.
How much does it cost to run a space heater?
A 1,500 W heater costs about 25 cents per hour at 17 cents per kWh, or around $38 a month at 5 hours a day.
What is a kilowatt-hour?
The energy used by a 1,000-watt device running for one hour. Your utility bills you per kWh.
Why is my real cost lower than the estimate?
Many appliances cycle and do not draw their full rated power all the time.