With the default inputs (Power rating 1500; Hours used per day 4; Days used per month 30; Number of devices 1; Electricity rate 18.34; State U.S. average (18.34¢/kWh)), this calculator returns Monthly Cost $33.01, Daily Cost $1.10 and Yearly Cost $401.65.
Every row is computed with this page's own calculator. Change the inputs above to model your own numbers.
| Power rating | Monthly Cost | Energy per Month |
|---|---|---|
| 10 W | $0.22 | 1.2 kWh |
| 60 W | $1.32 | 7.2 kWh |
| 100 W | $2.20 | 12.0 kWh |
| 500 W | $11.00 | 60.0 kWh |
| 1,000 W | $22.01 | 120.0 kWh |
| 1,500 W | $33.01 | 180.0 kWh |
| 3,000 W | $66.02 | 360.0 kWh |
Use this calculator to estimate how much electricity one or more appliances consume and what that energy costs. Enter the device's power rating in watts, the number of hours it runs each day, the number of days it operates per month, and the number of identical devices.
Enter the electricity rate in cents per kilowatt-hour, or select a state rate. The default U.S. average residential electricity price is 18.34 cents per kWh for June 2026. The state choices use rates from the same EIA table.
The results show energy use and cost by day, month, and year. These time periods make it easier to compare occasional devices with equipment that runs regularly.
Watts measure power, while kilowatt-hours measure energy used over time. Dividing by 1,000 converts watt-hours to kilowatt-hours. A device rated at 1,000 watts and operated for one hour uses exactly one kilowatt-hour.
Monthly energy multiplies daily energy by days used per month. Yearly estimates extend daily use across the corresponding annual period.
The default example uses a 1500 watt device for 4 hours per day, 30 days per month, with 1 device. The selected state option is U.S. average (18.34¢/kWh), and the entered electricity rate is 18.34 cents per kWh.
Multiplying 1500 watts by 4 hours and dividing by 1,000 gives the displayed daily consumption. Applying the selected rate produces the operating costs. The results are Monthly Cost: $33.01, Daily Cost: $1.10, and Yearly Cost: $401.65.
The corresponding consumption results are Energy per Day: 6.00 kWh, Energy per Month: 180.0 kWh, and Energy per Year: 2,190 kWh.
For equipment that cycles on and off, estimate actual active hours. Refrigerators, heaters, televisions, and other devices with thermostats or standby modes may draw less than label wattage on average.
A label wattage commonly represents a maximum rather than continuous average demand. Operating settings, cycling, standby behavior, age, and usage patterns can therefore change actual consumption. The result is an estimate based on the values entered, not a prediction of the complete utility bill.
To estimate a household bill with fixed charges, taxes, and fees, use the Electric Bill Calculator. To convert power and operating time directly into energy, use the Watts to kWh Calculator.