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Conservation | Appliances | Calculations
Seattle City Light, Appliances, Calculations
In order to calculate the energy consumption of an appliance, you will need to know how much power it draws and how long you typically use it. Somewhere on the appliance you should find a specification plate that tells you either the power demand in watts or the electric current it draws in amps. You can use the following equations to make your calculations:

W (watts) = amps x volts = amps x 120 (usually)
kW (kilowatts) = watts/1000
kWh (kilowatt-hours) = kilowatts x hours

If you want to figure out how much this usage costs, simply multiply the kilowatt-hours by the, average rate for electricity, 9.14 cents per kilowatt-hour for residential customers in Seattle. If you like you can use the automatic calculator on this page or consult the chart for typical costs and consumption for a variety of home appliances.

How many watts does your appliance draw?
 watts
OR if your appliance does not have wattage displayed
How many amps does your appliance draw?
 amps
AND
For how much time do you typically use the appliance?
 



Cost per average day = $ 
(An answer of zero in this box means this appliance
costs you less than a penny a day to run.)

OR
Cost on two month bill if you use it every
day on average = $
 

Contact an Energy Advisor
(206) 684-3800

SCLEnergyAdvisor@seattle.gov

Residential Conservation Programs & Services | Appliances Home