What Size Is an NBA Basketball? Detailed Guide for You

Are you an NBA enthusiast and love to dribble once in a while? If so, you must already have one or two basketballs at home. But did you know that basketballs have different sizes? That’s right. And depending on which league you play for, you need to use a specific ball size.
If you are curious about what size an NBA basketball is, this article sheds some light on the different basketball sizes and helps you choose the best ball based on your playing style.
What Size Is an NBA Basketball?
The official basketball size of an NBA ball has a circumference of 29.5 inches. This is also the same size of the basketball used in the college and high school basketball leagues.
The best-selling brands of basketballs are Nike, Spalding, and Wilson. Spalding is the official NBA and WNBA ball, while the other two brands have made a name for the variety of colors, technology, and textures they incorporate.
For the NCAA and the majority of the youth basketball leagues, Wilson is the ball of choice.
The History of Basketball Size in NBA
When you enter any large sports store, you must’ve noticed the elaborate display of different kinds of basketballs. These displays usually can tell the story of how the basketball we see today came to be its size.
It all started in 1891 when Dr. James Naismith was tasked with developing a new game for the winter. It led to the first-ever game of basketball being played, but back then, the ball that was thrown into the hoop was a soccer ball.
Dr. Naismith then contacted A.G. Spalding and Bros. in 1894, requesting their expertise to create a ball specific to the basketball game. The company developed a leather ball that was bound together by laces. The ball’s dimensions were 4 inches larger than the soccer ball, with a circumference of 32 inches.
In 1948, the basketball was re-invented to be slightly smaller, with a circumference of 30 inches. And this became the official size the following year.
Throughout the years, the appearance and materials used for the ball continued to be improved upon, transitioning from using leather to rubber or synthetic composite as the primary material used for the ball’s outer layer.
Regulation Sizes for Different Leagues
Different leagues use different sizes of basketballs depending on the players’ age, gender, and level of players. Here are the different basketball regulation sizes based on the basketball league.
#1. Women’s National Basketball Association (WNBA)
Women’s NBA uses a slightly smaller basketball than the men’s league. The ball used in WNBA has a diameter of 9.07 to 9.23 inches and a 28.5-inch circumference.
#2. National Collegiate Athletic Association (NCAA)
The balls used in the NCAA depend on the gender of the players. Men use balls between 9.39 and 9.55 inches, while women use the same standard as WNBA.
#3. International Basketball Federation (FIBA)
For international plays, particularly the FIBA, the basketballs used in these games are the Molten GL7 for men and Molten GL6 for women. These balls stand out from the other basketballs because they have two distinct colors and are a little bigger.
The men’s ball has a circumference of 30.7 inches, while the women’s basketball features a 29-inch circumference.
Which Size Basketball Is Right for You?
It’s a good idea to choose a basketball that’s suitable for your gender and age to make the sport more enjoyable without you having to exert unnecessary effort in handling the ball. Here are the most common sizes of basketballs and the recommended age category for them:
#1. Size 7 Basketball (29.5 inches)
Teenage boys 15 years old and above can use this ball. This is the official size of basketballs and weighs 22 ounces.
#2. Size 6 Basketball (28.5 inches)
These balls measure 28.5 inches and weigh the standard 20 ounces. Given their smaller dimension, size 6 balls are ideal for the smaller palms of women. They are used in WNBA and in women’s college and high school basketball leagues.
Most female youth leagues with players aged 12 years and older and middle-aged boys from 12 to 14 years old use this ball. It is thus also known as the intermediate ball.
#3. Size 5 Basketball (27.5 inches)
This is the recommended size of balls for boys and girls aged 9-11. It weighs 17 ounces and is sometimes called the junior ball. This is the standard ball that youth basketball leagues use.
#4. Size 4 Basketball (25.5 inches)
These balls are ideal for young players aged 4 to 8 because they are lightweight at only 14 to 16 ounces. This is why they are also used in younger basketball leagues.
#5. Size 3 Basketballs (22 inches)
These are your typical play balls that weigh 10 ounces and are recommended for the youngest players. This ball weighs a mere 10 ounces.