To determine whole-house generator sizing, the first step is for the homeowner to determine the number of appliances and electrical devices that will be run and calculate the total wattage.

Adding up the running watts and the highest starting wattage of all the devices you wish to power with a generator will help you determine the size of the generator you will need. Larger, whole-house ...

Total Wattage: 1,050 + 350 = 1400 watts The total wattage you need to run a small refrigerator would be 1400 watts, so you would need a generator that provided at least that many watts.

Your generator also must have at least a 30-amp/240-volt output. To calculate wattage for a standby generator, check a year's worth of electric bills to find the highest kilowatt usage.