Electricity Cost Calculator
Estimate how much it costs to run any appliance, based on its wattage, usage hours and your local electricity rate.
Result
Enter your numbers to see the estimate.
How this calculator works
Electricity bills can feel like a black box, but the underlying math is simple once you know an appliance's wattage. Power consumption in kilowatt-hours (kWh) is calculated as watts ÷ 1000 × hours used, and cost is simply kWh × your electricity rate per kWh.
This calculator asks for your appliance's wattage (often printed on a label on the device, or in its manual), how many hours per day and days per month you use it, and your electricity rate. We don't guess your electricity rate for you — rates vary enormously by location, provider and time of use, so enter the rate from your own utility bill for an accurate result.
Common household appliances vary widely in wattage: a TV might use 80-200 watts, a refrigerator cycles between 100-400 watts, a window air conditioner can pull 900-1500 watts, and a space heater often uses 1500 watts continuously. Larger appliances running for long hours — heating, cooling and water heating — are usually the biggest contributors to your bill.
Example: A 1500-watt space heater run 5 hours a day for 30 days, at $0.15 per kWh, costs about $33.75 for the month.
How it works
Enter your measurements or costs
Fill in the room size, materials or costs for your project. No sign-up required.
Adjust the settings
Choose your units, waste percentage and any project-specific options.
Get your estimate instantly
See your results calculated instantly, right in your browser.
Frequently asked questions
How is electricity cost calculated?
Power in kilowatt-hours (kWh) is watts ÷ 1000 × hours used. Cost is kWh multiplied by your electricity rate per kWh, which you'll find on your utility bill.
Where do I find my appliance's wattage?
Most appliances have a label with wattage (or amps and volts, which you can multiply) on the back, bottom or inside the door. Your appliance's manual will also list it.
Where do I find my electricity rate?
Your electricity rate (price per kWh) is listed on your utility bill, usually as a rate schedule. Rates vary by provider, location and sometimes by time of day.
Why doesn't this calculator include a default electricity rate?
Electricity rates vary enormously by country, region, provider and season, so we ask you to enter your own rate for an accurate estimate rather than guessing.
Can I compare two appliances?
Yes, see our dedicated appliance energy calculator, which lets you compare two appliances side by side.