If you have your electric bill how can you tell how big a generator you need to power all your stuff?

So I'm sitting looking at my electric bill and thinking about how big a generator I would need to power everything, but all the numbers are in kilowatt-hours, and generator are in strait kilowatts. I realize that a kilowatt-hour is a kilowatt in an hour, but, how does that relate the the output rating of a generator? So, with the monthly kwh ratings how can I tell how many kw I need at peak? (Like when all my computers are running and my AC. That's 983 kwh, by the way.