The size of the Gaga pit will vary based on the number of players. If you need to accommodate groups of 6 to 8, your Gaga Ball Pit should be 15 feet in diameter. For groups of 8 to 12, you will need a pit that is at least 20 feet in diameter from wall to wall. If your player groups typically include groups of 12 or more, your pit should be at least 25 feet in diameter. The height of the pit walls will be about 42”-44”. Typically you want a gaga pit that is high enough that kids cannot fall out of but also one that kids can see over. 42” high seems to be the perfect height.