Electricity Cost Calculator
Find out what any appliance costs to run. Enter its wattage, how many hours a day you use it and your electricity rate to see energy use and cost per day, month and year.
Electricity Cost Calculator
Find out how much energy a device uses and what it costs per day, month and year at your electricity rate.
Monthly figures use 30.42 days (365 ÷ 12). Taxes, fixed charges and time-of-use rates are not included unless built into your rate.
The formula
Cost = watts × hours ÷ 1,000 × rate per kWh
For example, a 1,000 W appliance used 4 hours a day uses 4 kWh daily. At $0.17 per kWh that is $0.68 a day, about $20.68 a month and $248 a year.
Finding your electricity rate
Your bill lists the price per kWh, often split into supply and delivery charges. For a realistic all-in figure, divide the total bill (minus any fixed monthly fee) by the kWh used. Average U.S. residential rates are roughly 15 to 20 cents per kWh, but they range from under 12 cents in some states to over 35 cents in others.
What common appliances cost to run
| Appliance | Watts | Use per day | kWh per month | Cost per month at $0.17 |
|---|---|---|---|---|
| Refrigerator (average with cycling) | 150 W | 24 h | 110 | $18.62 |
| Window AC, 10,000 BTU | 1,200 W | 8 h | 292 | $49.64 |
| Space heater | 1,500 W | 6 h | 274 | $46.54 |
| 55-inch LED TV | 120 W | 5 h | 18 | $3.10 |
| Desktop computer | 300 W | 6 h | 55 | $9.31 |
| Wi-Fi router | 15 W | 24 h | 11 | $1.86 |
| Electric water heater (average) | 4,500 W | 3 h | 411 | $69.81 |
Monthly figures use 30.42 days (365 ÷ 12). Your appliance’s actual draw may differ; a plug-in energy meter gives the most accurate number.
Grid power vs generator power
Running the same appliances on a generator costs far more per kWh. A 7,500 W gasoline portable at half load produces electricity for roughly 60 cents per kWh in fuel alone at $3.20 a gallon. That is several times the typical grid price, before maintenance and wear. Compare the numbers with our fuel consumption calculator and generator cost calculator.
Frequently asked questions
How do I calculate cost for appliances that cycle on and off?
Refrigerators, freezers, air conditioners and water heaters only draw full power part of the time. Either enter the running watts with the hours the compressor or element actually runs, or enter the average draw measured over a day with an energy meter.
Does this include taxes and fixed fees?
Only if they are built into the rate you enter. Time-of-use plans charge different rates at different hours, so use the rate for the hours you run the appliance.