It clearly depends on the size. If you have 2 people who weigh a little bit over the average, then two is probably the maximum. If you are looking at children, provided they are not obese, three would probably fit.
Two adults. If you do not mind touching other bodies when you sleep, you might be able to squeeze in a 3rd body if you are all relatively small.
One american
I have a double bed or full bed and I was just wondering how many people comfortably can sleep in a full size bed.
