Which option costs less to run?
Compare two devices or two ways of using the same device. Enter the power draw on its label, how long you use it, and the electricity rate on your bill.
Use the energy charge per kWh from your bill. This estimate excludes fixed fees and taxes.
Your estimated running costs
At the same rate, used on the schedule you entered.
Simple math, visible assumptions.
Daily energy = watts × hours ÷ 1,000. Daily energy × your rate gives daily electricity cost. Monthly estimates use 365.25 ÷ 12 days; annual estimates use 365.25 days.
Use average measured power for devices that cycle on and off. A nameplate maximum can overstate actual use. Time-of-use rates, variable tariffs, fixed charges, and taxes are outside this calculator.
Method: U.S. Department of Energy, Energy Efficiency at Home. For a rate starting point, see EIA electricity price data; your own bill is more relevant.