Utility bills don't show the costs of using individual appliances, so you can't use yours to determine how much electricity your refrigerator uses. With a few calculations, though, you can figure out how much electricity your refrigerator uses, how much it costs you and what impact it has on the environment.

### Calculating Kilowatts

Kilowatt-hours are the unit of electricity by which electricity companies charge you. To find out how many kilowatt-hours your refrigerator uses, you must first determine how many amps and volts it uses. Amps measure electric current and volts measure electric potential. When you multiply them together, the result is the number of watts your refrigerator uses. Look inside your refrigerator to find out its amperage and voltage. According to the Otter Tail Power Company (OTPC), most refrigerators use between 300 and 780 watts. To calculate how many kilowatts your refrigerator uses, divide its wattage by 1,000. A typical refrigerator uses 0.3 to 0.78kW of electricity.

### Comparing Other Appliances

Your refrigerator uses fewer kilowatts than other major appliances in your home. OTPC estimates that a dishwasher, for instance, typically uses 1.8kW of electricity. An oven uses 3.5kW and a clothes dryer uses 5kW. Despite this, your refrigerator costs more per month to operate.

### Impact

The amount of kW an appliance uses is important, but so is the number of hours for which you use the appliance. Electricity companies charge by the kilowatt-hour. So though your dryer uses 5kW of electricity, you use it significantly less than you use your refrigerator, and it accounts for less of your utility bill. According to OTPC, refrigerators typically run for 150 to 300 hours per month. Kilowatt-hours are kilowatts multiplied by hours of use, so your refrigerator may use as many as 234 kWh of electricity per month.

Electricity, on average, costs 11.2 cents per kWh as of 2011, according to the U.S. Energy Information Administration. At this price, your refrigerator can cost more than £16 to operate per month. Since a kilowatt of electricity usage amounts to 1.06kg. of carbon dioxide emitted into the atmosphere, your refrigerator may be the source of about 117kg. of air pollution per month.

### Reducing Usage

To reduce the amount of electricity your refrigerator consumes, set it to 4.44 degrees C --- the maximum the U.S. Department of Agriculture recommends --- and keep it stocked full. With less air to chill and with fewer degrees' difference between the air inside and outside the door, the refrigerator will require less power.

#### References

- University of Northern Iowa: Appendices
- Otter Tail Power Company: Appliance Energy Use
- U.S. Energy Information Administration; Average Retail Price of Electricity; March 2011
- U.S. Department of Agriculture; "Danger Zone" (4.44 degrees C to 60 degrees C); May 2010
- All You; 7 Easy Ways to Be More Energy Efficient; Lauren DiPilla