Common Household Appliance Energy Use
Listed below are some common appliances, their wattage and an estimate of operating costs. There is also a simple formula for calculating operating costs below.
In order to calculate the average operating cost for any electrical appliance you can use the following formula:
watts/1000 = kW x hours of operation = kWh x kWh rate = cost
Watts can usually be found on the appliance nameplate. If the nameplate lists amps:volts x amps = watts
Example: How much does it cost to operate my portable electric heater? Electric heater wattage is usually given on the unit itself, or with the literature that comes with it. An example is 1000 watts. I use the heater an average of 45 hours during winter months, Klickitat County PUD’s electric rate is $.0781.
1000 watts/1000 = 1 kW x 45 hours of operation = 45 kWh x $.0781 = $3.51 Now we have an 8 amp heater. The calculation changes just a bit:
8 amps x 120 volts household current = 960 watts/1000 = .96 kW x 45 hours = 43.2 kWh x $.0781 = $3.37