Why Do Tennis Balls Lose Pressure?

Do Tennis Balls Float?

If you are a tennis player at any level, you would have noticed tennis balls losing the air pressure that’s inside it and starting to behave differently. In this article we explore what are the possible reasons why a tennis ball loses pressure.

When tennis balls are being manufactured, the most crucial area is the pressurized-air inside the balls.

Rubber is used as a sealant for this air and can keep this air trapped in the ball. The balls have this air to enable them go for longer miles without falling once force is applied to them during a tennis game.

This is because the pressurized air inside the ball is lightweight, enabling the ball to move for longer distances. The pressurized air is also used to ensure that the balls are round and maintain that shape even after running into an obstacle.

That said, the tennis balls do lose the air that they contain for various reasons. These are listed and explained below.

Why Do Tennis Balls Lose Pressure & Air?

  • Constant Collision Between Racket & Tennis Ball
  • Drastic Pressure Difference Between Tennis Ball & Surrounding Area
  • Not So Ideal Storage of Tennis Balls
  • Tennis Surface in Question
  • Unideal Amount of Air in the Tennis Ball
  • Heat

When the Racket and Tennis Ball Collide During Play

Tennis is essentially a racket game that requires one player to hit a tennis ball towards their opponent and vice versa.

A lot of force is applied to the racket to enable the tennis ball to move faster and longer distances.

Tennis courts are about 2100 ft², and a single ball is needed to play around the court. To cover these vast distances, a lot of energy is required for the ball to go across the net.

When the tennis ball collides with a racket, the pressure in the ball increases, and the surrounding pressure is lower; this pressure dynamic causes the air to move from the ball to the environment.

Also Read:

When There’s a Pressure Difference Between the Balls and The Surrounding Area

The pressurized air at the center of the tennis balls is placed in ideal external pressure conditions to maintain the pressure balance between the ball and its environs.

When playing tennis, the balls are exposed to the atmosphere, which has a low-pressure system. This pressure is unable to hold the tennis ball’s internal pressure.

The tennis balls then tend to start losing this air into the atmosphere.

The Storage of the Tennis Balls is Not Ideal

When opening a tennis ball can, a hissing sound is heard coming from the container.

The can is filled with pressurized air that maintains the pressurized air inside the tennis balls. The cans are filled with the same pressurized air as the tennis balls.

The air ensures that the pressure in the ball is equal to the pressure outside the ball. It makes the density between them equilateral, and there is no air transfer between the two bodies.

Taking the balls out of the can exposes the tennis ball to a different and low atmospheric pressure.

The pressure difference now creates a dynamic that does not help keep the pressurized air intact in the ball. It leads to the air inside the ball being released to the outside environment, and over time the ball is unfit to be used during tennis games.

The Tennis Court Surface Being Used

There are different tennis courts like grass courts, hard courts, artificial grass courts, and clay courts.

When playing tennis, the play includes hitting a tennis ball on the court’s ground and the ball bouncing towards your opponent.

In so doing, the ball experiences wear and tear from continuously hitting the ground. As a result, the tennis balls become worn out, and the ball experiences loss in air pressure.

Hard courts impact the tennis ball more than the other tennis courts. Therefore, they render tennis balls unfit for use faster than the other tennis courts.

Also Read:

The Amount of Air Inserted into a Tennis Ball

Large-scale manufacturing companies make tennis balls in massive numbers using advanced technologies.

These technologies do not ascertain if the amount of air pressurized into the tennis balls is equal.

Therefore, when playing tennis, players test the balls with their hands to see whether or not these balls have enough air before serving the ball.

Using a tennis ball with less air would make the tennis balls release air faster than balls with a lot of pressurized air.


High temperatures cause air to get heated up and expand, and molecules move around the tennis ball. This further increases the pressure of the air inside the ball.

On the other hand, the rubber starts pulling apart and increases micro leaks in the tennis balls.

The air in the balls then begins escaping the ball and into the atmosphere. When the temperatures reduce, the remaining air in the balls condenses, and there is a decrease in the amount of air in the balls.

After losing air into the atmosphere, it does not return back to the ball.

Rubber is a suitable core sealant that does its job of containing air inside the tennis balls.

When the ball releases this air, the tennis balls cannot go back into the balls because of the high pressures inside the tennis balls that create an imbalance between the tennis balls and the atmosphere.

The rubber material plays a huge part in ensuring the air does not enter the tennis balls from the atmosphere.

Over time, the tennis balls lose air and are rendered unfit for use during tennis games. During a tennis ball play, you can realize a tennis ball has lost its pressurized air if:

  • The tennis ball becomes ‘flat.’
  • The tennis ball becomes harder to hit
  • The tennis balls are unable to move over long distances
  • The balls no longer bounce as they did before

Checking whether the tennis balls contain enough pressurized air is essential for a fair tennis game.

Checking the air can be done by squeezing the ball in your hand and checking how flaccid the balls are and if the tennis ball deforms or goes back to its original shape.

It is the easiest and most used method done on a tennis court. You can also bounce the ball against the court to see the amount of bounce the ball offers you.

The amount of time it takes for tennis balls to last varies according to various factors such as:

  • The difference in the amount of air put into the tennis ball
  • The force used to play the game
  • The number of times the ball hits the ground
  • The type of storage you choose after removing the balls from their cans

Due to these discrepancies, the exact amount of time the tennis balls last is not carved on stone.

For professional plays, the balls can take between one to six hours to play, while for lightweight plays, the tennis balls last for about one to four weeks.

If the ball is used for less than six hours during a professional play, the tennis ball lasts for about two weeks.

A tennis ball can last up to two years in an unopened can since the air in the can eventually leak from micro leaks experienced by the cans.

Final Words on Tennis Balls Losing Pressure

With that being said to make your tennis balls last longer, you can purchase pressure pumps that can be used to add pressure to the balls whenever they lose their air.

Although these pressure pumps are pretty expensive, they minimize the amount of waste that occurs from using many tennis balls at a time and discarding them when they are not suitable for use anymore.

Stan Boone

I am the editor of Racket Sports World. I love my tennis, pickleball and most of the other racket sports played around the world and started this blog as my way to help other racquet sports fans even as I learn, explore and improve by connecting with them. Tweet at https://twitter.com/StanBooneTennis.

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