The number of balls in a pinball machine varies depending on size and the game. The standard size for a pinball machine is 5 inches (127 mm) across and 5 inches deep, which can contain up to 12 balls, although this will vary depending on the layout of the table. For example, if you have an open space in the middle of your machine that travels down towards one or more targets or ramps then there is likely to be only room for one ball at a time in these areas. The largest pinball machine ever made is Attack from Mars, which has a playing surface of 24.5 x 8 feet (7.5 x 2.4 meters). This can hold 22 balls at once.