No messing around with a fancy intro; I’ll astonish you with other cute little tidbits relating to the ping pong ball later. Let’s answer your question first.

The diameter of a ping pong ball is 1.57 inches (or 4 cm). They weigh 0.095 ounces (or 2.7 grams).

There you go. Easy. You had a question, and Above House served (!) you an answer. Please manage your expectations around future questions, though. While I’m going to do my best to give you as much information about leisure goods as possible, I’m not gonna be able to tell you where you parked your Honda Civic when you went to the World’s Fair in 1984. That’s on you.

Back to the topic, those dimensions render a ping pong ball about the same size as a golf ball, which comes in at 1.68 inches. That’s pretty close, although I HIGHLY discourage you from playing ping pong with a golf ball. The damage to your ping pong table will be significant.

If you’ve crushed your last ping pong ball underfoot and the nearest Costco is closed, find yourself another activity. Break out your old Nintendo NES, or give your cat some attention. The ping pong ball has been lovingly designed for its purpose… nothing else will be an adequate replacement.

A Brief History of Table Tennis Balls

On the topic of the ball’s design, let’s take a quick look at the fascinating history of the tiny little orb. If you’ve read our article on the history of ping pong, you may have learned that the game was (probably) invented by bored British soldiers during their rather problematic incursion into India in the mid 19th century.

Necessity being the mother of invention (and Joola still about 150 years away from being launched), these gents did what I just recommended you don’t, and used a golf ball to bat around with hardcover books. Although, bear in mind that they were probably playing on military mess-hall tables that could survive a direct hit from some kind of ordnance.

Once the game made its way back to England, where ping pong became popular with the kind of person who owns rather flat surfaces they’d prefer not to pound with the spherical equivalent of brick, an alternative had to be found. Initially, a tightly wound ball of string was used, as was rubber, and in certain cases, champagne corks.

It was only in 1901 that an Englishman named Jack Gibb stumbled onto a novelty toy made of celluloid, which he realized would do nicely as a replacement for the troublesome champagne cork which was, no doubt, driving his household nuts with its unpredictable bounce.

So there’s a fun little fact for you. Ping pong balls weren’t invented for ping pong. I was made for an entirely different purpose – presumably also leisure-related – and then appropriated by ping pong enthusiasts. Good work, Jack Gibb!

Ping Pong Ball Regulations

Up until the year 2000, table tennis’ governing body, the ITTF (International Table Tennis Federation), had been quite comfortable just letting players use the celluloid balls Jack Gibb had discovered. Although there must have been some alterations in manufacturing processes and almost imperceptively small changes in weight, ping pong balls were largely unregulated, and the ITTF comfortable to just let players use the balls that were available on the market.

However, following the new millennium’s first Olympics (held in Sydney), the ITTF started flexing its muscles. Concerned with how accessible the sport was for an audience watching at home on their TVs or sitting in row ZZ of the arena, they decided to institute a number of rule changes – all aimed at making the game more attractive to a growing global audience.

This is obviously an indicator that the ITTF could foresee a near-future where the majority of the world’s collective attention span would be whittled away by social media, 2-second animated gifs, memes, bite-sized videos, and vapid listicles.

Among these rule changes was an increase in the size of the ping pong ball. Before the rule change, the ping pong ball’s dimensions were 2 mm smaller, a diameter of 38 mm.

Those of you who are scientifically-minded may already see why this would make table tennis more watchable. Even such a small increase in the ping pong ball’s surface area would result in greater friction with the earth’s atmosphere, slowing it down as a result. It would also, theoretically, decrease the amount of spin that could be imparted onto the ball.

The desired result was longer rallies, something all spectators love seeing. But wouldn’t longer rallies mean longer matches, the very thing the ITTF was trying to avoid? Yes! But this scenario was balanced out by changing the scoring system from a 21-point game to an 11-point game. So… longer rallies, but fewer of them. Gotcha, ITTF. Good thinking.

What are Ping Pong Balls Made From?

Celluloid has long been the material-of-choice for serious players, but as manufacturing technology advances, plastic balls are increasing in popularity since they are cheaper to produce. For a long time, celluloid what the only material capable of producing that signature gameplay, but plastics have come a long way, and now the ITTF is more than happy to allow innovation in this space.

Those of you who’ve seen Inglorious Basterds may be asking yourself: “Isn’t celluloid the material the good guys used to burn the Parisian theater at the end of the movie?” The answer is yes. Celluloid is HIGHLY flammable. I cannot stress this enough.

Do NOT mess with a ping pong ball and fire. Well, do it if you really want, but only if you’re a real adult and under controlled circumstances. Seriously, those things burn up in spectacular fashion. You’re literally playing with fire. My advice is to keep ping pong balls away from open flames at all times.

For those of you interested in some more scientific literature on the performance of celluloid versus plastic as a material for ping pong balls, some researchers have compiled a surprisingly thorough paper on the topic.

How are Ping Pong Balls Manufactured?

Machines. They do everything now, don’t you know? Don’t worry; I’ll get into more detail. I’ll even treat you to a fascinating video of the process a little later.

Before that, let’s have a look at what the ITTF has to say about the ping pong balls themselves in order to qualify as “official.”

  • It must be perfectly round
  • It must weigh 2.7g
  • It must be either orange or white in color
  • It must have a matte finish (as opposed to gloss)
  • It must be made from celluloid or similar plastics material

The majority of the world’s ping pong balls are manufactured by the adorably named Double Happiness company in Shanghai, China – a country where table tennis is virtually a religion.

The first step is to take a flat sheet of celluloid and immersed it in heated alcohol to give it the necessary softness. This sheet is then pressed into a mold, which produces perfect half-spheres and allowed to cool down and harden.

Once the edges of the spheres have been neatly trimmed to ensure the perfect shape, they are weighed, and any non-ideal anomalies are discarded, leaving only the halves that can be combined to form a perfectly round, perfectly weighted ping pong ball.

The joining process is quite delicate since there should be absolutely no evidence of a seam. This would significantly affect the consistency of the ball’s trajectory and bounce and, as you can imagine, would be a big no-no in the eyes of both the players and the ITTF.

Fortunately, this process has been perfected by Double Happiness. A visible seam is inevitable but is smoothed away by a mechanical process that gently chafes the ball to produce a perfectly round product.

As promised, here’s a fascinating video on the process, which I greatly oversimplified in my description above.

True Bounce

While this is a rule that applies more to the ping pong table than the ball, it’s worth mentioning that the ITTF have requirements regarding how the ping pong ball bounces off the surface of the table.

What the governing body insists on is that the ball bounces at a consistent height – something they refer to as “true bounce.”

Under ITTF rules, true bounce is measured as follows: if the ball is dropped from a height of 30 mm, it must bounce to a height of 26 mm. So, regardless of how a table tennis ball is manufactured or where it bounces on the table, this true bounce must be achieved.

Is There a Way to Fix a Damaged Ping Pong Ball?

Anyone familiar with the game of table tennis will be equally familiar with the profound frustration of how fragile these little orbs are. While good-quality ping pong balls are built to withstand even the most robust of rallies and smashes, there are a host of hazards that can dent or crack a ping pong ball.

Hitting balls into one of the net’s posts can cause damage and isn’t an uncommon occurrence. Nether is stepping on one of the things while you rush after in an attempt to stop it from rolling towards an open door or a set of stairs.

Chances are, if you’ve played enough ping pong, you’ve found some impressively innovative ways to damage these delicate little orbs. Begging the question, is there a way you can fix a crack or re-inflate a ball that’s been dented.

Let’s get the bad news out of the way first. A cracked ball is destined for the recycling bin or an ill-advised fire-based experiment. There’s nothing you can do to rescue this catastrophe. My advice is to always have a large collection of ping pong balls available wherever you’re playing.

A dented ball, on the other hand, can be salvaged. Here’s how.

The easiest way is to involve hot water. Immersing a dented ping pong ball in boiled water that’s been poured into a cup. will cause the air inside the ball to expand and gently push the dent back out. This is an almost foolproof way of fixing the problem. Just don’t make the mistake of dropping the ball into water that is STILL boiling; you’ll be creating a whole bunch of new problems.

Since ping pong balls are ridiculously buoyant, you will need to gently push the ball down into the water with a spoon to ensure that it’s fully immersed. Once the dent has popped out, remove it with the spoon, and allow it to dry on a towel. Easy.

Some Final Thoughts

Ping pong balls are fragile creatures with a fascinating history. Kowing where they come from and how they’re made is knowledge that may only be interesting to those obsessed with the game. How to fix a dented ping pong ball, on the other hand, is something every player should be aware of, even those who just play for fun.

I hope you enjoyed my lengthy and comprehensive treatise on the diameter of a ping pong ball. Feel free to browse around the rest of our site for more information on the sport and also where you can buy the best table tennis equipment for your specific needs – a good starting point is our guide to the best ping pong paddles.