Why Are Tennis Balls Pressurized? The Science Unveiled

By Lin
Last update:
why are tennis balls pressurized

Buying a new can of tennis balls is one of the many things tennis enthusiasts will do throughout their careers. Have you ever stopped to wonder why tennis ball cans are pressurized? What is the reason brands do this, and how does it affect the quality of a tennis ball? Why do tennis balls come in a pressurized can?

One of the main reasons tennis balls come in pressurized cans is to ensure they keep their quality from the production line to your practice or game time. Typically, a new tennis ball has an internal pressure of 14 psi or greater, which in a pressurized can remain that way until you open and use it. This gives the ball a bounce and keeps the rubber from degrading.

Are you curious about why else a tennis ball can is pressurized, or what happens if you don’t do this? Well, we have the answers: keep reading!

Table of Contents

Why Are Tennis Balls Packaged In Cans?

Tennis balls are packaged in cans because they allow the internal pressure of the ball and surrounding air to stay intact. As we said, tennis balls must be pressurized to at least 14 psi to retain their ‘new’ feel upon someone opening them.

Therefore, a bag wouldn’t be sufficient packaging, nor would a box, because air can escape and depressurize the tennis balls. You don’t want this to happen, or your new balls will have less bounce or elasticity than they usually would. Think of this as when the ball is pressurized inside the can: it stays the same until you open it.

If you’ve ever tried to play tennis with a worn-out ball, you’ll notice it doesn’t bounce as high/well as a brand-new one from the can.

How Much Pressure Is In A Tennis Ball Container?

Although this varies by brand and manufacturer, most tennis ball containers have an internal psi of 14.7-26.7. A new tennis ball should have at least 14 psi when you buy it, but many containers are pressurized to give it closer to 26.

Normal air pressure is roughly 14.7 psi, so a can of tennis balls is likely to be greater than this to retain their quality during shipping and on a store or warehouse shelf. Doing this also helps combat temperature changes inside and around the tennis balls, so it gets very scientific.

Note: Tennis balls are manufactured from a rubber compound with an internal pressure of around 14 psi, so this is the default.

The History Of Pressurized Tennis Ball Cans

vintage tennis balls cans

Although many of us have never purchased tennis balls outside of the pressurized can, there was a time when this had not been invented. In the late 1920s, Thomas E. Wilson & Co. and the Pennsylvania Rubber Company decided to begin manufacturing the first pressurized metal tubes to preserve tennis balls’ shelf life.

The pressure inside the can was at the same level as the tennis ball, between 12 and 14 psi. This essentially cut back on customer complaints and shipping damage to the products this brand had been making.

After all, when a tennis ball hits the ground for the first time, we want it to bounce high. Wilson & Co. and the Pennsylvania Rubber Company knew this, and the idea was born. We’ve seen tennis balls sold in tin containers, cartons, and, eventually, the plastic cans we all know and love today.

Our article on the history and origins of tennis may also be worth reading.

Pressurized vs. Non-Pressurized Tennis Balls

Pressurized and Non-Pressurized

For those wondering what the difference between pressurized and non-pressurized tennis balls is, this is significant. Pressurized tennis balls are the type we typically will think of: being sold in air-tight containers with a psi of 14 or greater.

Pressurized Tennis Balls

Pressurized tennis balls are the choice for professional and competitive tennis. Filled with pressurized air, they ensure a consistent bounce and liveliness on the court, ideal for precision and excitement in high-stakes matches.

Non-Pressurized Tennis Balls

Non-pressurized tennis balls excel in practicing alone for beginners. Without internal air pressure, they offer a different playing experience with reduced bounce, making them suitable for refining control and technique. Additionally, their durability and affordability make them practical for practice sessions.

How Long Do Pressurized Tennis Balls Last?

Most pressurized tennis balls will go bad after two weeks or 3-4 playing sessions. This is because as they are used, their internal psi decreases rapidly. You will notice a depressurized ball lacks bounce as you toss and hit it, which can be detrimental to a tennis match or practice.

Many professional tennis companies and training facilities stock hundreds of cans of tennis balls to ensure players never have to play with a lackluster ball. However, this does raise concerns over the long-term impact of such short-term consumerism, which is when we’d recommend using non-pressurized tennis balls.

Regardless, tennis balls are short-lived, so enjoy them and their pressure while you can.

Can You Pressurize Dead Tennis Balls?

Yes, there are ways to repressurize tennis balls that have lost their internal psi. Many tennis experts will use a cylinder where they stack three tennis balls, seal the cylinder, and then pressurize it. The balls are porous enough to repressurize.

However, you can also pump the balls like you would a tire, but that requires modification and may not be worth the struggle. Tennis balls are usually somewhat porous, so they lose internal psi. By placing them in a confined space and pumping pressure into it, you should be able to revive them.

Again, you can avoid replacing your tennis balls each week or two using solid ones, so that’s another alternative we recommend.

Should I Put Tennis Balls In The Dryer?

Many people put tennis balls in the dryer to make them fluffier and bounce better. Generally, doing this is more targeted towards helping with clothing, as they work as laundry balls to fluff and soften towels, sheets, etc.

Regarding the tennis balls’ advantage of being in the dryer, we don’t see much reason for it unless they become wet after practice. In that case, you should throw them into the dryer and see if they bounce when you head back out to the court.

How Do You Keep Tennis Balls Pressurized?

One of the best ways to keep a tennis pressurized is by storing them properly. You often want to keep tennis balls in a pressurized can or container/tube, which will help retain their psi. Remember, as the regular outside air touches a tennis ball, this can often lead to them losing bounce within as little as a week.

Most tennis players and coaches use a product called the ‘PressureBall,’ which has been tested up to 35 psi. You don’t want to keep tennis balls under that much pressure, as they could explode.

Here’s a video showing how one works:

Too much pressure isn’t a good thing, either.

What Can I Do If My Tennis Balls Are Dead?

If you notice any of your tennis balls are dead, there are some things to do with them. As mentioned, you can place the balls into a pressurized container, pumping more air into them.

However, if it’s been a while, tennis balls won’t be much use, and you might as well use them for chair legs or give them to a dog. Tennis balls are often a short-term investment, and their cost can add up quickly depending on how much you play.

A pressurized container is what many will recommend to extend a ball’s life by a week or two, but there isn’t a way to keep them perfect forever.

How Much Does A Can Of Tennis Balls Cost?

slazenger tennis ball

You can generally expect to pay $3-$10 per can of tennis balls. Again, tennis balls usually come in a pack of three, so this should be a month’s worth of balls for a single player who practices 1-2 times weekly.

There are bundle options for tennis balls, too, which is better for frequent players and anyone who owns a tennis club. Costco, Walmart, Amazon, and other tennis warehouse websites offer this deal.

Our article on the best tennis training equipment might also be worth checking out.


This article covered why tennis balls come in pressurized cans and how they lose their bounce once opened. It’s worth remembering that there are solid tennis balls (non-pressurized) that are great for people not wanting to buy new balls every few weeks, but these aren’t used for matches.

Photo of author


Editor of All Points Tennis and a huge Roger Federer fan, I've spent countless hours studying his moves, especially his forehand and one-handed backhand. I also love writing about all the technical stuff like rackets and strings. I'm super pumped to share my insights with fellow tennis lovers here.