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Ultimate Basketball Size Chart (By Age)

What basketball size is for kids? For youth? High school? Adults?

Confused about what basketball to get? Below is a helpful basketball size chart by age, gender, and more:

Size CircumferenceWeightDescription (age / gender / etc.)
Size 729.5” (75cm)22 oz (0.62 kg)NBA; Official men’s size; Men’s ages 13+
Size 628.5” (72.5cm)18-20 oz (0.51 –
0.57 kg)
WNBA; Official women’s size; Girl age 12+; Boys age 11-13
Size 527.5” (69.9cm)14-16 oz (0.4 – 0.45 kg)Youth (Boys and Girls) aged 9-11
Size 425.5” (64.77cm)14 oz (0.4 kg)Children (Boys and Girls) age 8 and under
Size 3 / mini22.5” (55.9cm)10 oz(0.28 kg)Novelty-sized, “mini” basketball

The chart above is a general guideline. For kids/youth, the proper basketball size will depend on each individual’s physical development (i.e. some kids develop a lot faster than others).

Also, remember that for young kids learning to play (and shoot a basketball), it is very important not to use a ball that is too big or too heavy. A size 7 basketball is actually over 50% heavier than a size 5 ball!

If the ball is too heavy, kids will overcompensate and develop bad habits trying to heave the ball, instead of using proper shooting technique.

Read on for a more detailed description of each basketball size:

Disclaimer: Hoop Dojo may receive a small commission if your purchase products through links on this page. It helps to support the website. Thanks!

Size 7 – Men’s Official Basketball Size

Steph Curry and the NBA use a size 7 ball.

Size 7 is the standard basketball size for men.

It is the size of the official NBA basketball, as well as FIBA men’s competitions (e.g. the Olympics). High school boys and college men’s basketball also use a size 7.

Boys will typically start using a size 7 basketball sometime during middle school (approximately age 13+).

When fully inflated (i.e. 7.5 – 8.5 psi), the size 7 basketball should measure 29.5″ (75cm) in circumference, and weigh approximately 22 ounces (0.62 kg).

Size 6 – Women’s Official Basketball Size

The WNBA and women’s leagues use a size 6 ball

Size 6 is the standard basketball size for women.

It is the size of the official WNBA basketball, and FIBA women’s competitions worldwide. High school girls, and college women’s basketball will also use a size 6 ball.

Boys aged around 11-13 may also use a size 6 ball (approximately grades 5-7).

When fully inflated (i.e. 7 psi), the ball should measure 28.5″ (72.5cm) in circumference, and weigh approximately 18-20 ounces (0.51 – 0.57 kg). These measurements are from the official WNBA rulebook.

Interesting note: The official FIBA 3×3 basketball is a size 6 circumference (28.5″), but has the weight of a size 7 ball (22oz.)!

Size 5 – Youth (age 9-11)

Some serious young hoopers

Size 5 is the typical “youth” size basketball that you will find in stores.

It is meant for elementary school kids (both boys and girls), aged around 9-11 years old. This is around Grade 3 to Grade 5.

When fully inflated (i.e. 7-9 psi), the ball should measure about 27.5” (69.9cm) in circumference, and weigh approximately 14-16 oz (0.4 – 0.45 kg).

If the ball seems to big for your kid, you opt for a size 4 basketball as it has a smaller circumference (see below).

Size 4 – Children (age 8 and under)

A size 4 basketball is meant for young children (boys or girls), typically under 8 years old.

It is probably the best size for kids just starting elementary school (grades 1 or 2), or even still in kindergarten.

When fully inflated (i.e. 7-9 psi), the ball should measure about 25.5” (64.77cm) in circumference, and weigh approximately 14 oz (0.4 kg).

Size 3 – Mini

Never too early to learn a killer crossover

Size 3 basketballs are also called “mini” basketballs.

Perhaps only very small children (under 5 years old) would play with a size 3 basketball.


Is a size 7 basketball for boys?

Size 7 is the standard men’s size basketball.

High school aged boys will also use a size 7 basketball. Younger boys (around age 11-13) may want to use a size 6 ball. Young elementary school boys would probably want to use a size 5 ball.

What size basketball for a 13 year old boy?

A 13 year old boy could use a size 7 or size 6 basketball.

Most 13 year old boys will eventually start using a size 7 ball (i.e. adult men’s basketball).

What ball does the NBA use?

The NBA uses a size 7 ball called the Wilson NBA Official Game Ball.


For adults, it is easy to pick a basketball size. Size 7 is for men, and size 6 is for women.

For kids/youth, it can be a bit complicated. High schoolers will typically use the same size ball as adults.

Middle school boys may use a size 7, or size 6 depending on age. Middle school girls will probably also use a size 6.

Elementary school aged children (girls or boys) will use either a size 5, or size 4.

Remember that kids all develop physically at different speeds. When I was in Grade 8 (about 13 years old), one guy in my grade was already dunking, while some others had yet to hit puberty. 😅

For some basketball recommendations, check out these posts: best indoor ball, best outdoor ball, best indoor/outdoor basketball

Let me know what you think:

What do you think about the basketball size chart? Do you agree or disagree with the age groups? What would you change?

Leave a comment below!

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Larry Lee

Larry Lee

Larry is a basketball addict, and the founder of Hoop Dojo. He started Hoop Dojo to share his love of the game and help the next generation reach their full potential.