The official size of the basketball used by the NBA is 29.5 inches in circumference). This is the same size used throughout mens college and high school basketball leagues). The WNBA uses a slightly smaller ball, measuring 28.5 inches in circumference). For international play, specifically FIBA, the basketball used is what’s called a Molten GL7 for men and Molten GL6 for women. These basketballs typically feature two different colors and are slightly bigger, with a 30.7-inch circumference for the men’s ball and a 29-inch circumference for the women’s. Boys and girls between the ages of 4 and 8 use a basketball between sizes of 22 inches and 24.5 inches in circumference, depending on the individual’s hand size. Basketball inflation and pressure regulations require an NBA basketball to be inflated to a pressure of 7.5 to 8.5 PSI.