How US electricity costs are calculated
Appliance kilowatt-hour (kWh) usage is calculated from the wattage rating and hours of daily operation divided by 1,000.
Cost is calculated using your utility provider's rate in cents per kWh based on US Energy Information Administration (EIA) state averages, plus optional monthly customer charges.
Worked example
For a 1,500-watt space heater operating 4 hours per day, 7 days per week, at the US national average rate of 16.5 cents per kWh:
Daily usage is 6 kWh. At 16.5¢/kWh, the running cost is $0.99 per day, $30.03 per month, and $360.36 per year.
Inputs for the US electricity cost calculator
Appliance power rating
Power rating in watts (W), as stamped on the appliance manufacturer label.
Usage hours per day
Average hours the device is powered on each operating day.
Days used per week
Days per week the appliance is in active use (1 to 7).
Electricity rate (cents per kWh)
Your local utility rate in cents per kWh (US average is ~16.5¢/kWh per EIA).
Monthly customer charge (optional)
Fixed monthly account or meter connection service fee on your electric bill.
CALCULATOR QUESTIONS
Electricity cost calculator US questions
What is the average electricity rate in the United States?
According to the US Energy Information Administration (EIA), the national average residential electricity rate is approximately 16.5 cents per kilowatt-hour.
How many watts is a typical US kitchen refrigerator?
A standard modern refrigerator consumes between 100 and 400 watts when running, averaging around 1 to 2 kWh of daily energy.