For a home generator, to estimate your power needs, in watts, make a  list of of each appliance in your residence. Take a close look at the manufacturer’s label on each appliance, these will show how much electrical power it consumes. In some cases, the figure will be given in amps. To calculate wattage, multiply the amps by the voltage of the electrical circuit the device uses. Here’s an example, if a hair dryer’s label says it uses 10 amps, and it plugs into a normal 110 volt electrical outlet, it consumes 10 X 110, or 1100 watts. Calculate your minimum requirements for each of the items on your list. Items that have compressors or other electric motors require a surge of power the instant they start, usually with a higher amount than the power level they need under normal operation. A refrigerator that consumes 600 watts, for example, may use 1200 watts at start up when the compressor starts. Many generator manufacturers’ websites describe these requirements for a number of items. Select the single item with the greatest starting power requirement. It is probably unlikely that more than one device will start at the same instant, use this single item to see what the generator’s peak power requirement is.