Electricity Cost Calculator: Appliance Running Cost per Month and Year
Enter an appliance’s power draw in watts, how many hours a day you use it, and your electricity rate per kWh to see the energy used and the cost per hour, day, month, and year. Pick a typical wattage for an air conditioner, fridge, or PC if you do not know yours, and set the number of units and days of use per month. Everything is calculated in your browser, and nothing you type is sent to a server. For unit math, try the Unit Converter; for sales tax, try the Tax Calculator.
🔒 Runs in your browser · Your data is never sent to a server
Find your rate on your utility bill. Use the total rate including delivery and fees for the closest result. The US average is roughly 0.17 USD per kWh.
Notes
- Wattage is a nameplate or typical figure. Appliances such as air conditioners and refrigerators vary their draw while running, so the real bill will differ.
- Standby power and fixed monthly charges are not included. Enter an all-in rate (with delivery charges and fees) to get closer to your actual bill.
- The yearly cost is the monthly cost times 12. For appliances you use seasonally, adjust the days and hours to match.
Glossary
Watt (W)
How much power an appliance draws at a given moment. It is printed on the label or in the manual. 1,000 W equals 1 kW.
Kilowatt-hour (kWh)
The amount of energy used: power multiplied by time. A 1,000 W appliance running for one hour uses 1 kWh, and the cost is kWh times your rate.
Electricity rate
The price you pay per kWh. Many bills split it into energy, delivery, and fee charges; adding them together gives the effective rate.
FAQ
How is the electricity cost calculated?
Energy in kWh is power in watts divided by 1,000, times hours of use. That is multiplied by your rate per kWh. For example, a 500 W air conditioner running 8 hours a day uses 4 kWh a day; at 0.17 per kWh that is 0.68 a day, or 20.40 over 30 days.
What if I do not know the wattage of my appliance?
Check the rating label or manual for the rated power. If you cannot find it, pick a typical appliance from the list to fill in a common wattage. If you only know volts and amps, multiply them to get watts.
Why does my real bill differ from the estimate for an air conditioner or fridge?
Those appliances cycle on and off and change their draw with room temperature, settings, and door openings, so they rarely run at the rated wattage all the time. The estimate uses a rated or average figure and excludes standby power and fixed charges.
Which electricity rate should I enter?
Use the per-kWh price from your bill, including delivery charges and fees, so the result is close to what you actually pay. If you are unsure, the default is a typical household rate you can adjust.
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