Understanding kWh (kilowatt hour)

  1. One kilowatt equals 1,000 watts
  2. The cost of using a 100 watt bulb for 10 hours equals 1 kWh
Our average cost per kWh for the average residential customer is 12¢. To calculate the average cost of electricity, use the example below:

To operate a 40 watt bulb for 24 hours:

40 watt bulb x 24 hours = 960 watts
960 watts = .96 kWh
.96 kWhx 12¢ = 11.52¢

Estimating the monthly cost of electric appliances

  1. Determine the wattage used by the appliance and estimate the number of hours used per month. Wattage information can usually be found on the back or bottom of the appliance.
  2. Use the following formula inserting 12¢ for your electric rate and 30 for the number of days in a month.
Wattage x hours used per day x 30 days x rate = estimated cost

Examples of wattage:

16 cubic ft refrigerator  725 watts 
coffee maker 900-1200 watts 
dishwasher  1200-1400 watts 
microwave  750-1100 watts 
clothes washer  350-500 watts 
clothes dryer  1800-5000 watts 
dehumidifier  785 watts 

Lowell Light & Power

127 N. Broadway  •  Lowell, MI 49331  •  Phone: 616.897.8402  •  Fax: 616.897.4082  •  www.lowell-light.org

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