How to pick a full house generator?

The electrical output of a generator is expressed in kilowatts.  Watts are calculated by multiplying the input voltage ( usually 120 volts for U S A residential wiring ) by the amperage required.  volts X amps = watts.  This number is then divided by 1000 ( kilo = a number X 1000).  So, if your home has a 100 amp fuse panel, you would need {120v X 100a =  12000 watts = 12 kilowatts} a 12 kilowatt generator to give you the same amount of electricity you are getting from the local power grid.  These are pricey and bulky.  Most people who want a generator will get one in the 5 to 6 kilowatt range, which will supply enough electricity for necessary appliances and some lights.  These are more economical to buy, more portable, and much more economical in regards to fuel consumption.