Find the right basketball size for any player by entering their age and gender. The Basketball Size Calculator returns the recommended ball size number, circumference, and weight — so you buy the correct ball the first time.
Recommended Ball Size
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Circumference
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Ball Weight
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Size Name
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Typically Used By
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Boys aged 12–14 should use a Size 6 basketball with a 28.5" circumference and a weight of around 20 ounces. This intermediate size helps younger male players develop proper dribbling and shooting mechanics before transitioning to the full Size 7 ball at age 15.
Women and girls ages 12 and older use a Size 6 basketball, which measures 28.5" in circumference and weighs approximately 18–20 ounces. This is the official size used in the WNBA, women's college basketball (NCAA), and girls' high school leagues.
The NBA uses a Size 7 basketball with a 29.5" circumference and a weight of 22 ounces. This is also the standard for men's college (NCAA) and high school basketball, and is recommended for boys ages 15 and older.
Using the right size ball helps players develop proper shooting form, dribbling control, and passing technique. A ball that is too large can strain small hands and promote poor habits, while a ball that is too small won't prepare players for the regulation size they'll eventually use in organized play.
Children ages 4–8 typically use a Size 3 basketball, which measures about 22" in circumference and weighs around 10–12 ounces. Its smaller, lighter design makes it much easier for young kids to handle, build confidence, and learn fundamental skills.
Most regulation basketballs should be inflated to between 7.5 and 8.5 PSI (pounds per square inch). The ideal pressure is printed on the ball's casing. A properly inflated ball should bounce back to about waist height when dropped from shoulder height.
Indoor basketballs are typically made from full-grain leather and designed for smooth hardwood courts — they offer superior feel but wear out quickly outdoors. Outdoor basketballs use rubber or composite covers that withstand rough concrete and asphalt surfaces. Composite balls work well for both surfaces and are a popular all-around choice.
Most 10-year-olds use a Size 5 basketball, which has a 27.5" circumference and weighs around 17 ounces. This is the standard youth size for boys and girls ages 9–11 and is commonly used in recreational and youth league play.