Though your refrigerator is constantly plugged in and running, it doesn't use nearly as much wattage as other appliances, such as your clothes dryer. Your clothes dryer uses more than six times as much wattage as your refrigerator, but you would likely use the dryer for fewer hours per month. Electricity usage is a matter of wattage and operation time. Remembering this fact is the first step toward lowering the amount of electricity your refrigerator uses.
Open your refrigerator and look for a sticker that lists technical specifications. Find the voltage and amperage of the refrigerator; for instance, you may see "115 V" and "6.5 amps." Multiplying these two numbers tells you how many watts your refrigerator uses -- in this case, 747.5 watts. Smaller refrigerators typically use about 350 watts, while larger models use as much as 780 watts.
Comparing Other Appliances
Your refrigerator's wattage is toward the higher end of the spectrum among the appliances in your home. Clothes dryers use a minimum of 1,800 watts but may use as much as 5,000 watts. Dishwashers use about 1,800 watts. DVD players, laptop computers and alarm radios all use 50 watts or less. Usage matters as much as wattage when it comes to your electricity bill.
Divide your refrigerator's wattage by 1,000 watts to convert it to kilowatts, the unit electricity companies use. The refrigerator in the previous example uses 0.7475 kilowatts of electricity at any given moment. Multiply the refrigerator's kilowatt usage by 225 hours — what the Otter Tail Power Company reports as mid-range usage — to estimate how many kilowatt-hours of electricity it uses per month. A refrigerator that uses 0.7475 kilowatts may use 168.2 kilowatt-hours per month, which costs just over $20 per month as of 2013.
Energy Star-certified refrigerators use less electricity than other models, especially refrigerators made before 1996. Look for the Energy Star label when purchasing a new refrigerator to save money on your electricity bill. Energy Star estimates that certified refrigerators use 20 percent less energy than conventional models.