Appliance Energy Use Calculator
What does that space heater (or fridge, or dryer) really cost? Enter its wattage and use to get the annual running cost.
Smart plugs and energy monitors
Learn moreWatts, hours and your rate
Running cost comes down to three things: how many watts the device draws, how many hours it runs, and your electricity rate. Big motors and heating elements (space heaters, dryers, AC) dominate the bill; small electronics barely register.
How it’s calculated & sources
Energy (kWh) = watts ÷ 1,000 × hours/day × days/year. Cost = kWh × your rate. Adjust the rate to your utility’s number for accuracy.
Benchmark: the U.S. average residential electricity rate is about 17¢/kWh (EIA, 2025), though it ranges from ~11¢ to over 40¢ by state.
Results update as you type and are general estimates, not personalized financial, tax, medical or legal advice. Verify with a professional.
Worked example
A 1,500-watt heater run 4 hours a day costs about 6 kWh/day — roughly $1.02/day, or $372 over a winter at 17¢/kWh.
Frequently asked questions
Where do I find the wattage?
On the appliance label or nameplate, often near the power cord. If only amps are listed, multiply amps × volts (120 in the U.S.) to get watts.
Why is my fridge cheaper than its wattage suggests?
Fridges cycle on and off, so they don’t draw full power all day. Use the yearly kWh on the EnergyGuide label, or estimate ~8 hours of compressor run time.