hmmmm, the calculator doesn't allow for members in a family. For example, living where I do, dh would have to drive to work every day, the house would still have to remain warm, the only thing that would change is how much garbage we would produce. We do produce slightly more garbage now than we did with only two of us but not much more. Our electric is actually lower as I am home to tend fires, but they didn't have a space for wood burning. We also use less gas than we did with two of us as I don't drive in to work every day like I used to. This test is way to generic to really give a whole picture.