Selecting the right basketball size is key to improving your game and ensuring comfort during play.
Whether you’re a professional player or a youth athlete, using the correct basketball size tailored to your age and skill level can significantly enhance your performance and experience on the court. Here is the official basketball size chart by age, along with circumference, diameter, and weight.
Basketball Size by Age: Quick Reference
| Age Group | Basketball Size | Used By |
|---|---|---|
| 5 to 8 | Size 4 | Boys & Girls |
| 9 to 11 | Size 5 | Boys & Girls |
| 12 to 13 | Size 6 | Boys (Women & Girls 12+) |
| 14 and older | Size 7 | Men, Boys, NBA/NCAA/HS |
Official Basketball Size Chart (Full Comparison Table)
| Size | Circumference | Weight | Usage |
|---|---|---|---|
| Size 4 | 25.5 inches | 14 ounces | Designed for young children, size 4 basketballs are significantly lighter and smaller, making it easier for kids to grip and shoot the ball. It’s an excellent choice for beginners to learn the fundamentals. |
| Size 5 | 27.5 inches | 17 ounces | Perfect for youth players, this size allows younger children to handle the ball comfortably, aiding in skill acquisition and overall game enjoyment. |
| Size 6 | 28.5 inches | 20 ounces | Standard for women’s professional leagues, and boys’ middle school basketball. |
| Size 7 | 29.5 inches | 22 ounces | Standard for the NBA, men’s college, and high school basketball leagues. It is designed to enhance dribbling, shooting techniques, and overall handling for advanced male players. |
NBA Official Basketball Sizes
The NBA Youth Basketball Guidelines provide a comprehensive framework for structuring youth basketball competitions. According to the Youth Basketball Guidelines, these are the following recommendations for age groups by basketball size.
| Size | Recommended Ages |
|---|---|
| Size 5 | Boys & Girls Ages 7-8 |
| Size 6 | Boys Ages 9-11 Girls Ages 12+ |
| Size 7 | Boys Ages 12+ |
How To Choose the Right Basketball
- Consider the Playing Surface. Indoor basketballs are typically made of leather materials for a better feel and grip on smooth courts, while outdoor basketballs are made of more durable rubber to withstand rough surfaces.
- Test the Grip. Ensure the basketball has a good grip and texture, especially for younger players who might struggle with a slippery ball.
- Check the Inflation. Proper inflation, between 7.5 to 8.5 psi for sizes 6 and 7 and 7.0 to 8.5 psi for sizes 4 and 6, is crucial for maintaining the ball’s shape and bounce. Overinflated balls can be too hard and difficult to control, while underinflated balls may not bounce properly.
- Try Out First. Whenever possible, have players handle and test the basketball to ensure it feels right for their hand size and skill level.
For adults or those playing at a highly competitive level, a professional-sized ball (Size 7) is recommended. Younger players should choose a ball that matches their age group to promote skill development and enjoyment of the game.
Find the Right Basketball Hoop to Match
Knowing the correct basketball size is only half the equation, the hoop needs to fit the player too. Browse our full range of basketball goals to find a setup suited to any age or skill level, from in-ground basketball hoops built for growing players moving up to a size 7 ball, to adjustable basketball hoops that let you lower the rim for youth players still using a Size 4 or Size 5 balls. If space is tight, a wall mount basketball hoop is a great option for driveways and garages.
Not sure where to start? Check out our How to Buy Guide or see recommended court dimensions for the space you have.
Basketball Size FAQs
What is the official basketball size?
The official basketball size is Size 7, 29.5 inches in circumference, and 22 ounces, used in the NBA, men’s NCAA, and high school boys’ leagues. Women’s leagues, including the WNBA and NCAA women’s basketball, use an official size 6 ball at 28.5 inches.
Is there a quick basketball size guide I can reference?
Yes, use this basketball size guide as a fast rule of thumb: match the player’s age to the chart above, always size down rather than up for young children, and re-check sizing every year since kids often move up a size within 12 months as their hands grow.
Does basketball size change for indoor vs. outdoor play?
No, the size number stays the same indoors or outdoors. What changes is the material. Indoor basketballs are typically full-grain or composite leather, giving better grip and feel on smooth hardwood courts. Outdoor basketballs use durable rubber covers that hold up to asphalt and concrete without wearing down as fast. If a player splits time between a home driveway hoop and an indoor gym, a composite (indoor/outdoor) ball in their correct age size is the most versatile choice.
Do all basketball hoops work with every basketball size?
Yes, a regulation 18-inch rim fits sizes 3 to 7. Younger players may still find a lowered rim height easier to shoot on with a properly sized youth ball.