What size basketball should a player use?

How to choose the right basketball size:

We’re often asked, “Which basketball should I buy for my son or daughter?” The answer depends on several factors — including the player’s age, gender, and level of play. Basketballs come in four standard sizes used in organized games: 29.5", 28.5", 27.5", and 25.5" in circumference.

Below, you’ll find details on each size, along with the recommended age groups for every level.

Use this handy basketball size chart to determine which basketball is best for you or your player(s):

29.5" (Size 7) Basketballs

Men and boys ages 15 years old and older use basketballs that measure 29.5" in circumference and weigh 22 ounces. 29.5" basketballs are also referred to as "official size" or "size 7" basketballs. Men's leagues such as the NBA, college and high school use 29.5" basketballs. For boys, a 29.5" basketball should be used for ages 15+.

28.5" (Size 6) Basketballs

Women, girls ages 12+, and boys ages 12-14 use basketballs that measure 28.5" in circumference and weigh 20 ounces. 28.5" basketballs are also referred to as "intermediate" or "size 6" balls. Women's leagues including the WNBA, college and high school use 28.5" basketballs. Girls in 12+ leagues and middle school boys (ages 12-14) also use 28.5" basketballs.

27.5" (Size 5) Basketballs

It is recommended that boys and girls ages 9 to 11 use basketballs that measure 27.5" in circumference and weigh 17 ounces. 27.5" basketballs are also referred to as "junior" or "size 5" balls. The 27.5" circumference is the most common ball size used in youth basketball leagues.

25.5" (Size 4) Basketballs

Boys and girls ages 5 to 8 are recommended to use basketballs that measure 25.5" in circumference and weigh 14 ounces. 25.5" basketballs are also referred to as "rookie" or "size 4" basketballs.

Why Using the Proper Basketball Size Matters

Using the right basketball size is essential for developing strong fundamentals in dribbling, passing, and shooting. For young players especially, the correct ball size and weight help them build proper technique and good habits from the start. When a basketball is too large or heavy, it can lead to poor form — such as incorrect hand placement on shots or improper dribbling control — that becomes harder to correct later on.

In addition, playing with the wrong ball size can make the game frustrating. If a basketball is difficult for a player to handle, grip, or shoot, they may lose confidence and interest in playing altogether.

Choosing the appropriate basketball size helps players develop skills more effectively, enjoy the game, and stay motivated to keep improving — setting them up for long-term success on the court.

How Much Air Pressure Should A Basketball Have?

The standard recommended pressure for most basketballs is between 7.5 and 8.5 PSI. PSI stands for pound per square inch.

You can measure the pressure of a basketball using a simple pressure gauge tool. Insert the gauge into the valve and compare the reading to the recommended PSI. Adjust the air pressure by adding or releasing air as needed.

A properly inflated ball should retain its round shape. It should feel firm, but should also give slightly when squeezed.

You can also test that the ball is properly inflated by bouncing it against a hard surface. Notice the sound the ball makes. If it’s crisp and clear, you have the optimal amount of air pressure. If it makes a dull thud sound, you’ll want to pump more air into it. If you notice the ball makes a sharp, high-pitched noise, this indicates the ball is over-inflated.

By regularly checking your ball’s air inflation, you can maintain its optimal performance and you will know you are training with the best possible equipment to hone your skills.

Comparing Indoor & Outdoor Basketballs

The main difference between indoor and outdoor basketballs is in the material. Indoor basketballs are made of either full grain leather, synthetic leather, or composite leather. Generally, it takes a few uses for a full grain leather indoor basketball to be "broken-in," and thus easier to grip. A leather basketball should not be used outdoors because the concrete surface of an outdoor court causes the leather to roughen and wear, ultimately ruining the ball's grip. Both composite and synthetic leather indoor basketballs do not require a "break-in" period like a full-grain leather ball. However, the overall quality of composite and synthetic leather balls is less than that of regular leather basketballs.

Outdoor basketballs or "street balls" are made of rubber and are durable enough to withstand concrete surfaces without affecting the ball's grip. The grip on a rubber basketball is generally easier to control, making them a good ball to use for beginning players.