Basketball (size 7) Size & Weight
Basketball (size 7) Size & Weight measures ⌀241.0mm. It weighs about 624.0g.
Dimensions
| Diameter | 241.0 mm |
|---|---|
| Weight | 624.0 g |
Ask someone how big a basketball is and they will hold their hands about a foot apart. They are close. An official size 7 basketball is about 241 mm (9.5 in) across and measures 749 to 780 mm (29.5 to 30.7 in) around. That is the ball used in the NBA, FIBA, NCAA men’s, and high-school boys’ basketball, and it has barely changed in decades.
This guide covers the full size 7 specification, how it compares to a size 6 and a size 5 ball, how it stacks up against things around your house, and a few facts that most size pages leave out, including why two basketballs cannot fit through the rim at the same time.
Quick Answer: How Big Is a Size 7 Basketball?
A size 7 basketball has a diameter of about 241 mm (9.5 in), a circumference of 749 to 780 mm (29.5 to 30.7 in), and weighs 567 to 650 g (20 to 22 oz). The NBA’s official ball sits near the top of that weight range at 623 g (22 oz) and is inflated to 7.5 to 8.5 psi.
| Attribute | Metric | Imperial |
|---|---|---|
| Diameter | ~241 mm | ~9.5 in |
| Circumference | 749 – 780 mm | 29.5 – 30.7 in |
| Weight | 567 – 650 g | 20 – 22 oz |
| NBA official weight | 623 g | 22 oz |
| Inflation pressure | 51 – 59 kPa | 7.5 – 8.5 psi |
| Radius | ~120.5 mm | ~4.74 in |
Size 7 Basketball Dimensions at a Glance
- Diameter: ~241 mm / 24.1 cm / 9.5 in
- Circumference: 749 – 780 mm / 74.9 – 78.0 cm / 29.5 – 30.7 in
- Radius: ~120.5 mm / 4.74 in
- Weight: 567 – 650 g (20 – 22 oz); NBA ball ~623 g
- Surface area: roughly 1,820 cm2 (282 in2)
- Volume: roughly 7.3 litres (445 in3) of air when inflated
- Standard: FIBA / NBA size 7, the official men’s ball
What Does a Basketball Look Like in Size?
A size 7 basketball is almost exactly the size of an adult human head, just a little rounder and slightly larger. If you can picture holding a person’s head in two hands, you are picturing a basketball.
Put another way, its 241 mm diameter is a bit wider than a sheet of A4 paper (210 mm) turned sideways, and it is just under the length of a standard 30 cm school ruler. Held at arm’s length it blocks out roughly the same area as a dinner plate seen face-on.
The ball is big enough that most adults cannot palm it comfortably. Spreading a hand fully, the average adult span is about 210 to 220 mm, so the fingers barely reach around a 241 mm ball, which is why palming one is a recognised skill rather than a given.
6 Everyday Comparisons That Help You Picture a Basketball
- A soccer ball (size 5): about 220 mm across. A basketball is roughly 21 mm bigger in diameter, noticeable side by side but not dramatic.
- A bowling ball: fixed at 218 mm across. A basketball is about 23 mm wider, yet a bowling ball can weigh up to 7.3 kg against the basketball’s 0.62 kg.
- A sheet of A4 paper: 210 mm wide. Stand a basketball on the short edge of a sheet of A4 and the ball overhangs both sides by about 15 mm.
- An adult human head: roughly 22 to 25 cm from chin to crown. A basketball is right in that range, which is why “about head-sized” is the fastest way to describe it.
- A large dinner plate: usually 260 to 280 mm. The basketball’s silhouette is a little smaller than the plate.
- The rim: an NBA hoop is 457 mm across on the inside. One basketball (241 mm) leaves about 108 mm of gap on each side. Two balls side by side are 482 mm, so they physically cannot pass through the rim together.
Basketball Size in Different Units
| Measurement | mm | cm | inches |
|---|---|---|---|
| Diameter | 241 | 24.1 | 9.5 |
| Circumference (low) | 749 | 74.9 | 29.5 |
| Circumference (high) | 780 | 78.0 | 30.7 |
| Radius | 120.5 | 12.05 | 4.74 |
Most official rulebooks specify the circumference, not the diameter, because it is easier to measure with a tape around the ball. The ~241 mm diameter is simply the circumference divided by pi.
How Much Does a Basketball Weigh?
A size 7 ball weighs 567 to 650 g. Where it lands depends mostly on the cover material:
| Ball type | Typical weight | Where it is used |
|---|---|---|
| Full-grain leather (indoor) | 610 – 625 g | NBA, top-level pro and college |
| Composite / synthetic leather | 580 – 620 g | Indoor and outdoor club play |
| Rubber (outdoor) | 560 – 600 g | Playgrounds, driveways, schools |
All of them share the same ~241 mm diameter and circumference. The rubber ball feels lighter and bounces harder off concrete; the leather ball is heavier, grippier, and meant for a wooden floor.
Basketball Sizes by Age and Level
| Size | Circumference | Diameter | Weight | Who uses it |
|---|---|---|---|---|
| 7 | 749 – 780 mm (29.5 in) | ~241 mm | 567 – 650 g | Men and boys 12+, NBA, FIBA, NCAA men |
| 6 | 724 – 737 mm (28.5 in) | ~231 mm | 510 – 567 g | Women and girls 12+, WNBA, NCAA women |
| 5 | 690 – 710 mm (27.5 in) | ~221 mm | 470 – 500 g | Youth, ages 9 – 11 |
| 3 | 558 – 580 mm (22 in) | ~180 mm | ~300 g | Mini basketball, ages 4 – 8 |
The jump from a size 6 to a size 7 is only about 10 mm of diameter and 3 cm of circumference, but players feel it immediately in their grip and shot.
Why the Rim Fact Matters
The hoop’s inside diameter is 457 mm (18 in) and a size 7 ball is 241 mm. That leaves a total of 216 mm of clearance, about 108 mm per side, which is why a clean shot still needs to be reasonably accurate. It also means two basketballs cannot go through the same rim at once (2 x 241 = 482 mm, which is 25 mm more than the rim). Commentators mention “room for two balls” as a figure of speech, but the geometry does not allow it.
Common Mistakes When Comparing Basketball Dimensions
- Confusing circumference with diameter. A size 7 ball is 749 – 780 mm around but only ~241 mm across. Quoting 750 mm as the “size” without saying it is the circumference makes the ball sound four times bigger than it is.
- Using one fixed weight. There is no single official weight. The legal range is 567 – 650 g, and a rubber outdoor ball can sit well below a leather indoor ball.
- Assuming all adult balls are size 7. Women’s and WNBA basketball uses size 6, which is about 10 mm smaller in diameter.
- Ignoring inflation. An under-inflated ball measures the same but deforms on contact, which changes how big it plays even though the tape reading is unchanged.
- Treating a basketball and a soccer ball as the same. They look similar, but the basketball is about 21 mm larger across and roughly 200 g heavier.
Frequently Asked Questions
How big is a basketball in cm?
A size 7 ball is about 24 cm across and 75 – 78 cm around.
What is the diameter of a size 7 basketball?
Approximately 241 mm (9.5 in).
What is the circumference of an NBA basketball?
Between 749 and 780 mm (29.5 – 30.7 in). The NBA ball is at the lower end, about 29.5 in.
How much does an NBA basketball weigh?
About 623 g (22 oz), within the 567 – 650 g legal range for size 7.
Is a men’s and women’s basketball the same size?
No. Men use size 7 (~241 mm), women use size 6 (~231 mm).
How does a basketball compare to a soccer ball?
A basketball is bigger: about 241 mm across versus roughly 220 mm for a size 5 soccer ball, and around 200 g heavier.
Can two basketballs fit through the hoop at once?
No. Two balls are 482 mm wide and the rim is only 457 mm across.
What pressure should a basketball be?
The NBA specifies 7.5 to 8.5 psi. A common test is a 1.8 m drop that should bounce back to about 1.3 m.
Final Takeaway
An official size 7 basketball is about 241 mm (9.5 in) across, 749 – 780 mm (29.5 – 30.7 in) around, and weighs 567 – 650 g, with the NBA’s leather ball near 623 g. It is roughly the size of an adult head, a touch bigger than a soccer ball or a bowling ball, and wide enough that only one can pass through the rim at a time.
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Frequently Asked Questions
How much does a Basketball (size 7) Size & Weight weigh?
A Basketball (size 7) Size & Weight weighs about 624.0g.