To determine the size of the generator needed, total the rated watts of the appliances and fixtures you’ll want to operate during an outage. Some loads are easy to determine -- a 100-watt light bulb, for example, uses 100 watts. Ten 100 bulbs would require 1,000 watts, or 1 kilowatt (KW). The power requirements for appliances are often provided in the operating manual. These specifications are also stamped on the “face plate” along with serial and model numbers.

While the power needs of individual appliances vary, those that produce heat or use large motors tend to require higher wattages.

As you can see, a household’s power requirements can quickly add up.