Calculating Appliance Energy Consumption
You can estimate an appliance's energy consumption with the following formula:
The number you receive from using this formula will show you the appliance's daily kilowatt-hour (kWh) consumption. If you use the appliance for about the same time every day, you can multiply that number by 365 to determine annual consumption. Then, multiply that number by your utility company's rate per kWh.
Note that that number is an estimate. Many appliances use more energy as they get older. Also, some appliances that are plugged in and turned on all the time aren't always running. This formula does not work as well for appliances such as refrigerators, water heaters, and dehumidifiers, which cycle on and off throughout the day. Most experts suggest calculating a refrigerator's consumption based upon the premise that the compressor is only running 8 hours per day.
Gas appliances' power consumption is usually measured in joules or megajoules. (A megajoule is one million joules.) Multiply that number by hours used, then by your gas company's per-unit rate.
Many appliances consume more or less energy depending on how you use them. You will save a lot of energy by washing your clothes in cold water, by not using the dry cycle on your dishwasher, or by playing the radio just loud enough to hear.
Most appliances use tiny amounts of "phantom energy" when they are not running. You can unplug the appliances whenever they're not in use, but that will likely only make a small difference in your total electric bill.
- Multiply the appliance's wattage (which usually appears on the appliance) by the number of hours you use it in a day.
- Divide that number by 1,000.
The number you receive from using this formula will show you the appliance's daily kilowatt-hour (kWh) consumption. If you use the appliance for about the same time every day, you can multiply that number by 365 to determine annual consumption. Then, multiply that number by your utility company's rate per kWh.
Note that that number is an estimate. Many appliances use more energy as they get older. Also, some appliances that are plugged in and turned on all the time aren't always running. This formula does not work as well for appliances such as refrigerators, water heaters, and dehumidifiers, which cycle on and off throughout the day. Most experts suggest calculating a refrigerator's consumption based upon the premise that the compressor is only running 8 hours per day.
Gas appliances' power consumption is usually measured in joules or megajoules. (A megajoule is one million joules.) Multiply that number by hours used, then by your gas company's per-unit rate.
Many appliances consume more or less energy depending on how you use them. You will save a lot of energy by washing your clothes in cold water, by not using the dry cycle on your dishwasher, or by playing the radio just loud enough to hear.
Most appliances use tiny amounts of "phantom energy" when they are not running. You can unplug the appliances whenever they're not in use, but that will likely only make a small difference in your total electric bill.