A 9-to-11-year-old plays with a size 5 basketball (27.5 inches around); ages 5–8 use a size 4, and girls from 12 plus boys 12–14 move to a size 6. Size 7 — 29.5 inches, the men’s regulation ball — is for 15 and over. Ball size is set by age and gender, not by how good the player is.
The wrong ball is the most common reason a young player develops a two-handed push shot from the hip: a ball too big for their hand cannot be shot properly, so they invent a way to throw it instead. That habit takes years to unlearn.
Basketball size by age chart
| Size | Circumference | Weight | Age | Also called |
|---|---|---|---|---|
| Size 1 | 15.7″–16″ | — | 2–4 years | Micro-mini |
| Size 3 | 22″ | 10 oz | 4 and under | Mini |
| Size 4 | 25.5″ | 14 oz | 5–8 years | Junior |
| Size 5 | 27.5″ | 17 oz | 9–11 years | Youth |
| Size 6 | 28.5″ | 20 oz | Girls 12+, boys 12–14 | Intermediate / women’s |
| Size 7 | 29.5″ | 22 oz | Boys and men 15+ | Official / men’s regulation |
Girls and women stay on a size 6 permanently. That is the regulation ball at high school, college and professional level — it is not a junior size they grow out of. This trips up a lot of parents buying a first “proper” ball for a teenage daughter.
Hoop height by age
USA Basketball recommends 8 feet for ages 7–8, 9 feet for ages 9–11, and the full 10 feet from 12 up. If you are buying an adjustable home hoop, this is the setting that matters far more than the backboard size.
| Age | Rim height | Ball size |
|---|---|---|
| Under 7 | Below 8 ft, matched to height | Size 1–3 |
| 7–8 | 8 ft | Size 4 |
| 9–11 | 9 ft | Size 5 |
| 12+ | 10 ft (full height) | Size 6 or 7 |
Lowering the rim is not making it easy — it is the only way a child can shoot with proper form instead of heaving the ball. A seven-year-old shooting at a ten-foot rim learns to throw from the chest with both hands, because that is the only way to reach.
Indoor or outdoor ball?
Outdoor balls are rubber or composite and survive concrete; indoor balls are leather and are ruined by it within a few sessions. If your child mostly plays on a driveway, buy the outdoor ball regardless of what their team uses indoors — a leather ball is a expensive way to learn this lesson.
Does the ball need to be inflated to a specific pressure?
Yes, and it matters more than people expect. Most balls are marked with a target of around 7 to 9 PSI. Under-inflated is the more common problem: it kills the bounce, and a child who cannot dribble comfortably assumes the fault is theirs.
Sources and verification
Ball sizes and circumferences above are the standard sizing used across youth basketball and cross-checked between published guides. Rim height recommendations by age follow USA Basketball’s published youth guidelines. Leagues vary — confirm your specific league’s ball size and rim height before buying.
Last verified: 6 August 2026. Spotted a number that looks wrong? Tell us — corrections get the chart re-checked and re-dated.
More charts: every kids size chart in one place.
