How Big is a Ping Pong Ball? (Weight, Diameter & Size FAQs)

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Most people can picture ping pong balls in their heads, but they tend to overestimate the size and the weight of the ball. In our special "How Big is a Ping Pong Ball Guide", we'll answer all of your questions about size, weight, and dimensions.

ping pong balls close up

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How Big Is a Ping Pong Ball?

Ping pong balls are quite small. These perfectly spherical balls are made specifically for use playing ping pong. They have a diameter of 4 cm or 1.57” and only weigh 2.7 g, or .095 ounces. The official ping pong ball used to be a bit smaller, at just 3.8 cm, or 1.5”.

They have a 12.56 m, or 4.94” circumference. Generally, however, people talk about ping pong balls in terms of their diameter, not their circumference.

While they don’t vary much in size, ping pong balls can vary in color. Orange balls are great for casual games since they are so easy to spot, while white balls are official tournament balls. This is because they pair so well with either green or blue tables and are easy to see.

Which Is Bigger – A Ping Pong Ball or a Golf Ball?

It can be difficult at first glance to tell if a golf ball or a ping pong ball is bigger, but once you measure the balls, then you can easily see the small difference. Ping pong balls increased in size after the Olympic Games in 2000, but are still rather small at just 4 cm in diameter. This increase in size did bring them much closer to the size of golf balls, but they are still a bit smaller.

ping pong ball vs golf ball

Golf balls, on the other hand, are 4.267 cm in diameter, or 1.6”. These minimum sizes increased from 1.62” in 1990.

While you may have trouble telling which ball is larger simply by looking at them, most people can easily tell which one is heavier when they pick them up. Golf balls weigh significantly more than ping pong balls do, which is due to their design and construction so that they will easily soar through the air when hit.

Are There Different Sizes of Ping Pong Balls?

Ping pong balls are generally available in two sizes – 3.8 cm and 4 cm. The 3.8 cm balls are the old balls, while the 4 cm balls are the ones that are currently the recommended size. This means that if you are going to be setting up a local tournament or want to practice for a real official tournament, then you need to make sure that you use the right size balls. If you do not, then you may struggle during the real game.

Another thing to consider when shopping for ping pong balls, in addition to the size that you choose, is their quality. Not all balls are made the same, and not all have the same purpose, which means that you need to be able to choose the best one for your needs if you want to have luck behind the table.

Fun, or novelty, balls are designed in lots of different colors and may even come in different sizes. They are geared towards children who want to play ping pong and need a little extra incentive to enjoy the sport. While they look fun on the table, they often vary in size and can be either hard or soft, making it difficult for more dedicated ping pong players to find the right balls for their needs.

ping pong ball sizes and colors

Training, or practice, balls are another type of ping pong ball available on the market. They tend to be softer and are generally the standard 4 cm, although it is possible to find them in the 3.8 cm size. Unfortunately, they are not very durable and can easily break if they are hit too hard.

One-star balls are great for youth or use at schools. While they are still a little softer than higher-quality balls, they are fun and easy to play with. They can range in colors and sizes, but most often are available in 4 cm sizes.

Two-star balls are great for practice, use with a robot, or by intermediate players. They are not the highest quality ball on the market, but they can easily be used in a pinch if necessary. As long as they are the correct weight and are 4 cm in diameter, then they can be used for tournaments.

Finally, the best ping pong balls on the market are three-star balls. They have been authorized for use by the International Table Tennis Federation and are the perfect choice for professionals and more serious players. Ping pong players are generally safe to assume that any three-star ball they buy will be the correct size for play.

How Heavy Is a Ping Pong Ball?

To be authorized for use in tournament play, ping pong balls need to be 2.7 g in weight. Any heavier than this and the players will have to hit the ball much harder to get it over the net. Balls that are any lighter will be incredibly difficult to hit and to control, making the game harder than it needs to be.

Are Ping Pong Balls Hollow?

Ping pong balls are completely hollow on the inside, which is why they are so light. They are made from celluloid that has been extracted from cotton cellulose, as well as plastic. While there has long been a rumor that ping pong balls are filled with camphor, the truth is that they are not, and they only have air on the inside.

Ping pong balls go through an interesting creation to become their perfectly spherical and hollow shape. There are large and flat sheets of celluloid that are soaked, fully submerged, in hot alcohol until they are soft. Once they are soft and pliable, then they are pressed into half-spheres. These hemispherical shapes are trimmed and allowed to harden completely. Once this occurs, then two shapes are joined together with an alcohol-based glue.

Once the two halves have been joined together, then the ping pong ball is inserted into a machine where the edges will be smoothed down and the surface will be smoothed, as well. Finally, the ping pong ball will be stamped and then packaged.

At no time during the process are any strange gases inserted into the ping pong ball. This interesting process results in a perfectly hollow and spherical ball every single time.

How Many Ping Pong Balls Can Fit in a Swimming Pool?

swimming pool

A 12’ by 24’ swimming pool would require 16,562 ping pong balls to simply cover a single layer in the pool. This is impressive enough, but if the pool were 8’ deep, then that number jumps to 2,629,269. Most people simply can’t wrap their minds around this many ping pong balls.

An Olympic-size swimming pool, on the other hand, with a recommended depth of 9’10” will require 151,125,952 ping pong balls to fill it from top to bottom.

Sometimes, people have a hard time wrapping their minds around the size and the incredibly low weight of ping pong balls, which is why it’s fun to image them filling up common objects around the home. Anyone who has both a swimming pool and a ping pong table at their home has probably wondered, at some point, how many ping pong balls they would need to be able to completely fill up their pool.

How Many Ping Pong Balls Can Fit in a School Bus?

While this may seem like a strange question to ask, it’s actually a popular interview question that prospective employers love to ask during interviews. This is because it requires a lot of in-depth thinking and reasoning by the person trying to solve the problem. Standard school buses are about 8’ by 6’ by 20’. Based on the size of a ping pong ball, as well as how much volume is available to fill in an empty school bus, there will generally be around 1,095,529 balls inside of the bus to fill it up.

school bus

As you can see, you would have to have a shocking amount of ping pong balls to fill up a standard school bus. Most people are surprised by how many balls they would need for this task, as it can be impossible to even imagine having that many balls.

A lot more goes into choosing great ping pong balls than simply buying the first package that you see at a store. It’s incredibly important to make sure that you are always aware of the size and quality of ping pong ball that you are looking for so that you can be sure you make the right choice for your needs. Skimping by buying low-quality balls or ones that aren’t the authorized 4 cm size will result in you having problems with your games and not being prepared for real tournament play.