Use an appliance wattage chart to calculate the electricity costs of appliance operation and to avoid overloading household outlets or circuits. Multiply wattage by daily hours of use and divide by 1000 to reach kilowatt-hours consumed. Avoid exceeding 1,500 watts per outlet or electrical circuit.
Multiply daily kilowatt-hours by 30 for monthly consumption. Use rate per kilowatt-hour to determine the cost of operating the specific appliance. Know which outlets are connected to the same circuit. Don't exceed two appliances per outlet or plug appliances that use 1,000 watts or more, such as microwave ovens, space heaters and air conditioners, into the same outlet or circuit.
Appliance wattage charts give typical watts, which can vary by model. Check the appliance for more accurate information. The amount of electricity use varies depending on how an appliance is used, for example if hot water rather than cold is used in a washing machine. Many appliances use small amounts of electricity even when they are not in operation.
Wattage is the rate at which electricity is consumed per hour by an appliance. When 1000 watts, or 1 kilowatt of power, is used for one hour then 1 unit or kilowatt-hour of electricity is consumed.