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.
