Making sure you give players the appropriately sized basketball for their age and gender is incredibly important. But with several official sizes to choose from, it’s easy to be confused about which basketball size is actually the right one.
In this guide, we’re going to go through the various basketball sizes so that you can establish the correct size for optimal player development. Beyond that, we’re also going to talk about why the size of the ball can impact player development and discuss other important sizing considerations.
Sizing Must Be Consistent
Before we start looking at the different available basketball sizes, there’s one thing we need to get out of the way first. And that’s the importance of consistency.
Players should be practicing and playing with the same size balls. So even if you have a child who is being taught at school with a ball that is slightly too small or big, the best thing to do is get them a ball of the same size.
You might think it’s better to have children practice with the ‘correct’ size at home, but this can throw them off and make things feel awkward when they play games at school.
Why Does The Size Of The Ball Matter?
While it might be tempting to fast-track youth players to use a full-sized basketball, a basketball that is too big and heavy can make ball handling difficult and even develop poor habits—like flinging the ball, instead of shooting it, to reach the net.
The reason is two-fold. First, there’s obviously the issue of the physical size of the ball, which is usually measured as a circumference in inches. There’s just no way a younger ball with smaller hands can cradle or control a full-size ball properly.
Second, balls of different sizes also differ in weight. A ball that’s too heavy makes passing, shooting, and receiving more difficult. The player will have to end up compensating and compromising form.
All this added difficulty not only makes it harder to build good fundamentals but also makes basketball a whole lot less enjoyable for the player. And for young kids, just making sure they are having fun is the most important thing!
Basketball Size Chart
Here’s a table comparing the common basketball sizes: 3,4,5,6 and 7. For each size, we’ve also included the age range as suggested by popular basketball manufacturers:
| Age Guidelines by Brand | |||||
|---|---|---|---|---|---|
| Size | Circumference | Weight | Baden [1] | Spalding [2] | Wilson [3] |
| 7 | 29.5” | 22 oz | Men and boys 15+ | Men and boys 13+ | Men and boys 12+ |
| 6 | 28.5” | 20 oz | Women and girls age 12+ Boys ages 12-14 |
Women and girls 9+ Boys 9-12 |
Women and girls 9+ Boys 9-11 |
| 5 | 27.5” | 17 oz | Boys and girls 9-11 | Boys and girls under 9 | Boys and girls under 8 |
| 4 | 25.5” | 14 oz | – | – | Ages 4-8 |
| 3 | 22.0” | 10 oz | – | Novelty (all ages) | – |
Notice the large discrepancy between the manufacturers’ age recommendations, despite the balls being made to the same specifications. And herein lies the issue, there’s no absolute consensus on basketball sizes when it comes to youth basketball!
From our experience, many sports equipment brands like Spalding and Wilson generally recommend basketballs that are slightly too big. And that is likely a factor why it’s common to see boys start middle school with men’s official size 7 basketballs or 9-year-olds with size 6 basketballs.
For us, the most ideal basketball size guidelines based on age is the following:
| Size | Our Age Range Recommendation |
| 7 | Boys 14+ |
| 6 | Boys and girls 11-13 |
| 5 | Boys and girls 8-11 |
| 4 | Boys and girls under 8 |
What are the official guidelines?
Basketball sizes for adult competitions are well defined. Size 7 is universally the official ball size for men’s basketball according to the rules of the NBA, NCAA, and FIBA international leagues. High school basketball leagues for boys also play with this size.
Size 6 is the official size for women’s games according to WNBA, Women’s FIBA, and Women’s NCAA.
Youth guidelines are more varied, but the USAB established youth basketball guidelines in 2016 which are the following:
| Playing Segment | Size of Ball | Height of Basket | Size of Court | Distance of 3-Point Arc | Distance of Free-Throw Line |
| Ages 7-8 | Boys and Girls size 5 (27.5”) | 8’ | 50’x42’ | Not applicable | 14’ |
| Ages 9-11 | Boys and Girls size 6 (28.5”) | 9’ | 74’x50’ | Not applicable | 14’ |
| Ages 12-14 | Girls size 6 (28.5”) Boys size 7 (29.5”) | 10’ | 84’x50’ or 94’x50’ | 19’9” | 15’ |
| Grades 9-12 | Girls size 6 (28.5”) Boys size 7 (29.5”) | 10’ | 94’x50’ | 22’2” or the next available line under 22’2” | 15’ |
The size of ball guidelines set out by the USAB is quite aggressive, meaning smaller players or those growing slowly could struggle. This is especially the case when compared to guidelines set out in other countries, such as Basketball England, which goes up the sizes at a slower pace.
Non-Standard Youth Basketball Sizes
Because basketball sizing can be tricky for younger players, there are also basketballs that don’t conform to the standard regulation balls.
Examples include Spalding’s “Rookie Gear” series, which are sized according to regulation balls but are 25% lighter. The idea behind these balls is to help players who lack strength practice their shooting technique with a specific ball size.
There are also balls of other sizes and even shapes that are used as training tools during basketball drills.
Other Important Considerations
The size of the ball is the most important consideration when buying younger players the right equipment, but you need to be aware of other factors that can impact their play.
The most obvious is the height of the rim, as getting a ball above a 10-foot regulation rim is too challenging for developing players. Ideally, you’ll want an adjustable hoop that can grow with the player.
The quality of the ball is important too. The player might grow out of a youth-sized ball quickly so it’s not worth buying the most expensive ball, but you should make the choice between an indoor or outdoor basketball depending on where the ball will be played.
