Energy Usage Formula

Wondering How Much Energy Your Appliances Really Use?

Use this simple formula to calculate your appliance consumption.
Wattage X hours used per day X number of days used ÷ 1000

1500 watt space heater used 10 hours a day for a 30 day billing period.
1500 X 10 = 15,000 X 30 days = 450,000 ÷ 1000 = 450 kWh used.
450 kWh X $.105 = $47.35 per month

Don’t know the watts?
Volts X Amps = Watts
Ex. (120 V X 10 A = 1200 W)
You can usually find the wattage of most appliances stamped on the bottom or the back of the appliance or on its nameplate.

acec usage calculator

energy use and cost


located on device you are using

KW Cost

energy cost

Hours Per Day

Select Hours

Cost Per Hour


Cost Per Day


does not apply to all rates