The U.S. Department of Energy (DOE) has a handy on-line calculator to check how much it costs to operate your home appliances. It's a great tool for comparing how much energy new appliances use compared to your current appliances. You can use the information on the new appliance EnergyGuide Label to find the appliance that will give you the best value over time.
The Appliance Energy Calculator allows you to estimate your annual energy use and cost to operate specific products. The wattage values provided are samples only; actual wattage of products varies depending on product age and features. Enter a wattage value for your own product for the most accurate estimate.
Determining how much electricity your appliances and home electronics use can help you understand how much money you are spending to use them. Use the information below to estimate how much electricity an appliance is using and how much the electricity costs so you can decide whether to invest in a more energy-efficient appliance.
There are several ways to estimate how much electricity your appliances and home electronics use:
To find out how many watts of electricity a device is using, just plug the monitor into the electrical outlet the device uses, and then plug the device into the monitor. It will display how many watts the device uses. If you want to know how many kilowatt-hours (kWh) of electricity the devices uses in an hour, or a day, or longer, just leave everything set up and read the display later.
Monitors are especially useful for finding the amount of kWh used over any period of time for devices that don’t run constantly, like refrigerators. Some monitors will let you enter the amount your utility charges per kilowatt-hour and provide an estimate how much it cost to run the device since it was plugged into the monitor.
Many appliances continue to draw a small amount of stand-by power when they are switched "off." These "phantom loads" occur in most appliances that use electricity, such as televisions, stereos, computers, and kitchen appliances. Most phantom loads will increase the appliance's energy consumption a few watt-hours, and you can use a monitor to estimate those too. These loads can be avoided by unplugging the appliance or using a power strip and using the switch on the power strip to cut all power to the appliance.