Other contributors have said "How many millimeters are in a foot?" is the same question as "How many millimetres are in a foot?" If you believe that these are not asking the same thing and should be answered differently, click here
Ummm . . . there is 1 square foot in a square foot. The square foot could be any dimensions, like 1 foot by 1 foot, or half a foot by 2 feet, or a quarter of a foot by 4 feet . . . . .