The official size of the basketball used by the NBA is 29.5 inches in circumference. That’s the same size used throughout men’s college and high school basketball leagues.
These are size 7 basketballs and all men’s professional basketball associations including college and high school basketball leagues use the same ball. The NBA used to get all its basketballs from Spalding which was producing NBA’s official game balls since 1983. However, the NBA switched to Wilson after the 2019-20 season.
For kids younger than 10 and older than 5, the basketball recommended is of size 5. This of course depends on the size and capacity of a child, but that is the trend. For the official professional matches of the NBA, the size 7 ball is brought into use. Before bringing in the game, the basketball goes through several tests of all requirements.
The standard for a basketball in the National Basketball Association (NBA) is 29.5 inches (75 cm) in circumference and for the Women's National Basketball Association (WNBA), a maximum circumference of 29 inches (74 cm). High school and junior leagues normally use NCAA, NBA or WNBA sized balls.
The standard basketball size is 7 – 29.5 inches in circumference. It is the official size of the NBA league and all the professional basketball leagues for men. However, the standard size for women is 6 – 28.5 circumference.
Size : Circumference : Weight : Recommended For: Size 7: 29.5" 22 oz: Men and boys ages 15 and up. This is official size for high school, college, and the pros. Size 6: 28.5" 20 oz: Boys ages 12-14. Girls and women ages 12 and up. This is the official size for women’s high school, college, and pro basketball. Size 5: 27.5" 17 oz: Boys and girls ages 9-11 years old.
To begin with, the NBA basketball is produced by Spalding, and the official size for men’s tournaments has to be 29.5 inches in circumference. With a weight of 22 oz., the ball can be inflated with a pressure range of 7.5 to 8.5 psi.
The typical size of a basketball for all ages goes as follows: Boys aged 13 and older: Size 7 ball (29.5 inch circumference, 22 oz., used at the men’s professional level) Boys aged 10-12, Girls aged 11 and older: Size 6 ball (28.5 inch circumference, 20 oz., used at the women’s professional level)