The size of a basketball is pretty standard. The official NBA size 7 basketball has a circumference of 29.5 inches (75 cm). This is also the official size for men’s NCAA basketball and boys high school basketball.
Since younger boys, girls and women often have smaller hand sizes, there are smaller size basketballs for younger levels of basketball play. The smaller sizes allow those with smaller hands to be able to handle the basketball better and make shooting the ball a little easier as well.
My Personal Experience
I have had the pleasure of coaching basketball for young kids, and I can tell you that the smaller youth size basketballs really make a difference. The young kids are able to handle the smaller basketballs much better. The lighter weight really allows them to shoot better and get the basketball up to the hoop.
It really helps with their confidence and gets them started on learning the fundamentals. As kids grow, they are able to gradually move up to an official size basketball and remain confident in their skills.
What is the Official Size of a Basketball?
Let’s take a look at the size, circumference, weight and use for each size of a basketball. The following chart can be handy if you’re trying to figure out what size of basketball your child should start using.
| Size |
Weight |
Circumference |
Age Group |
| Size 7 |
22 oz (1.38 lbs or 0.62 kg) |
29.5 inches (75 cm) |
This is the official size of the NBA, NCAA Men’s and boys highschool. Recommended for men and boys ages 15 and up. |
| Size 6 |
20 oz (1.25 lbs or 0.57 kg) |
28.5 inches (72 cm) |
This is the official size of the WNBA, Women’s College and girls high school. Recommended for Women and girls ages15 and up. Boys ages 12 – 14. |
| Size 5 |
17 oz (1.06 lbs or 0.48 kg) |
27.5 inches (70 cm) |
This is the standard youth size basketball that you will see in many youth leagues. Recommended for boys and girls ages 9 – 11. |
| Size 4 |
14 oz (0.88 lbs or 0.40 kg) |
25.5 inches (65 cm) |
Recommended for boys and girls ages 5 – 8. |
| Size 3 |
10 oz (0.63 lbs or 0.28 kg) |
22 inches (56 cm) |
This is known as a “mini” basketball and recommended for boys and girls ages 4 – 8. |
| Size 1 |
8 oz (0.50 lbs or 0.23 kg) |
16 inches (41 cm) |
This is known as a “micro-mini” and recommended for boys and girls ages 2 – 4. |
Additional Resources
As you can see there are multiple sizes of basketballs made for different age groups and leagues. The different sizes are made by many of the different basketball manufacturers. Spalding has a great website showing the difference in the basketball sizes. Take a look if you want to find out more.
Which basketball size should you use?
The official weight and size of an NBA basketball is 22 ounces (1.38 lbs or 0.62 kg) and 29.5 inches (75 cm) in circumference. There are quite a few other basketball sizes made for different leagues and age groups.
The youth-size basketballs are a great tool to help kids learn and gain confidence as they start playing basketball. If you are unsure of what size basketball to use, just check the chart above. I hope this provides useful information to anyone who has questions about basketball weights and sizes.
Have you ever used a smaller size basketball just for fun? We’d love to hear from you, so please leave your comments if you would like.
