Circumference of a Basketball Hoop

As a young hoops fan, I remember watching an old NBA Slam Dunk Contest where a player held two basketballs preparing for a dunk. “What is he going to do with two basketballs,” I wondered. 

Just then, he took off and dunked both balls into the hoop. I couldn’t believe it. The dunk almost broke my young basketball brain. Do two basketballs fit into the hoop at the same time?

As an older fan, the dunk doesn’t resonate the same, but as a youngster, I thought it was amazing. I had never seen two balls go through the hoop simultaneously like that. 

For those who have never seen something like this, check out this video of the Harlem Globetrotters for an idea of what my young eyes saw.

Let’s dig a little deeper to see if two basketballs next to each other could, in fact, fit into the hoop at the same time, or if my young eyes were playing tricks on me.

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Can Two Balls Fit In The Hoop?

The answer is no by a few small inches. That means every basketball camp counselor or coach who told you that they could is a liar (just kidding coaches!).

Let’s break down the math:

A basketball hoop’s diameter – the length from one side of the hoop to the other – clocks in at 18 inches


The diameter of an NBA basketball is between 9.43 and 9.51 inches. Why can the measurements differ? Because it all depends on how much air and pounds per square inch (PSI) are in the ball. 

The more air, the wider the ball even if it is by a small fraction. So simple math shows that two NBA regulation basketballs measure between 18.86 and 19.02 inches, causing a logjam at the rim if attempted to push through together.


While many places on the internet report that two WNBA balls fit in the hoop together, their info is incorrect. Let’s look at the math and see why.

A WNBA ball’s diameter is 9 inches, making two balls 18 inches, or exactly the diameter measurement of a regulation rim. But if you add the circumference of each – 56.5 inches for the hoop and 29 inches for each WNBA ball – you would rule out the chance that two balls would fit in the rim together. 

That means the diameter of two WNBA balls is exactly 18 inches, the same diameter as the hoop. The circumference of two WNBA balls, however, is 57 inches, and the hoop’s circumference is only 56.5 inches. This makes it mathematically impossible to fit both balls at once. 

Youth Basketball

If you are a youngster using a kid’s basketball, then you are in luck! 

A children’s basketball’s diameter measures a circumference of 27.5. Multiply that by two and you get 55 inches, an inch and a half smaller than the regulation hoop’s 56.5-inch measurement. 

Most youngsters don’t have the athletic ability to dunk a couple of balls together and will never have to worry about this, but it could come in handy playing knockout, and your ball barely goes in before your opponent’s.

Basketball & Rim Measurements: Why They Matter

If situations, like having two balls enter the rim together, rarely occur, then why did we spend so much time on this subject? The biggest reason is that it shows just how much room there is for a basketball in a hoop. 

As a shooter, your best opportunity to make your shots is to put as much arc – how high you shoot the ball – under it as possible. Now that you know that two basketballs can almost fit into the rim together, it gives you a perspective of your room for error as a player.

The more arc added to your shot, the better angle that your shot enters the rim. If you shoot a line drive at the rim, your margin of error is almost nothing. But a nice high-arcing shot? You can miss a couple of inches long or short and still have a chance of making the shot.

Final Thoughts

The old myth that two basketballs can fit into the rim together has been debunked. It’s ok though because you don’t use two balls when you play basketball. The information, however, can still be utilized in your favor as you look for tips on how to become a better shooter

Adding more arc underneath your shot can only strengthen your chances of making shots. Now that we know the rim is almost the size of two balls, we can become more confident in our shot.

Did you still think two balls could fit in one hoop? Let us know if we blew your mind below!

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