What are the Sizes of Basketballs?

Dr. James Naismith had not codified any specifications for a uniform basketball size when he introduced the game in a YMCA in 1891 in Springfield, Mass. The first games were played with a peach basket and a soccer ball. However, basketball's rule books now specify the size of basketballs at all levels of play, down the inch and the ounce.

  1. Boys' and Men's Basketballs

    • From the time a male basketball player enters junior high, the basketball he will use in competition will feel the same all the way through his career, even if he makes it to the pros. A regulation men's basketball, used for scholastic, collegiate and professional competition, will measure between 29.5 and 30 inches in circumference and weigh 20 to 22 ounces. Although the appearance might be deceiving, two regulation basketballs can fit side-by-side through a rim, which measures 18 inches in diameter.

    Girls' and Women's Basketballs

    • To the eye, a women's regulation basketball looks exactly like the men's. The ball features eight panels and four seams, or channels, measuring no more than a quarter-inch, just like the men's ball. But to the touch, the difference in the ball is instantly noticeable. A women's basketball measures is an inch smaller in circumference, 28.5 to 29 inches, and it is lighter, weighing 18 to 20 ounces. The smaller, lighter ball should also produce a slightly lower bounce off the court than a typical men's basketball.

    Youth Basketballs

    • Basketball players ages 8 through 12 typically use a regulation women's basketball, inflated to the same weight and dimensions, in competition. The smaller size of the ball is ideal for younger players still learning the basics of how to handle and shoot the ball, and who are developing the strength to execute the game's fundamental movements. Youth-league players 7 or younger employ a junior-size basketball smaller than the women's basketball, checking in at 27.25 to 27.75 inches in circumference and 14 to 16 ounces.

    Extra-Strength Basketballs

    • Although they might never see the court for competitive play, oversize basketballs such as JumpUSA.com's The Big Ball, the Baden SkilCoach or the Champion Sports XXL Oversized Trainer can be valuable training tools. An oversized basketball forces a shooter to improve his accuracy, while also developing strength in the fingers, forearms and upper body for ball handling. Oversize basketballs can also be utilized by post players for improving strength when finishing shots around the basket and above the rim.