standard basketball size
Basketballs typically range in size from very small promotional items only a few inches in diameter to extra large balls nearly a foot in diameter used in training exercises to increase the skill of players.The standard size of a basketball in the NBA is 9.5 to 9.85 inches (24.1 to 25.0 cm) in diameter.asketballs typically range in size from very small promotional items only a few inches in diameter to extra large balls nearly a foot in diameter used in training exercises to increase the skill of players.