Another option:
(multiply number of grids times the inches per grid)
2x14=28
3x14=42
(12 inches per foot, so divide each of those by 12)
28/12=2.33
42/12=3.5
(multiply the two together and you have square feet)
2.33x3.5=8.155 square feet
I do not see where the home page states that the size of a 2X3 is 7.5 square feet just that, that is the minimum space to provide one guinea pig. A 2X3 cage is the closest rectangle you could make for 7.5 square feet without making the cage only one grid wide.
(multiply number of grids times the inches per grid)
2x14=28
3x14=42
(12 inches per foot, so divide each of those by 12)
28/12=2.33
42/12=3.5
(multiply the two together and you have square feet)
2.33x3.5=8.155 square feet
I do not see where the home page states that the size of a 2X3 is 7.5 square feet just that, that is the minimum space to provide one guinea pig. A 2X3 cage is the closest rectangle you could make for 7.5 square feet without making the cage only one grid wide.