Tennis balls seem like a commodity: a can of three or four yellow balls, pick any brand. In reality, balls differ in construction, felt, speed and intended surface, and those differences change how the game feels — and how quickly a can goes flat. Choosing the right ball is cheap, easy and noticeable from the first rally.
What is inside a tennis ball
A standard ball is a hollow rubber core covered with felt, a blend of wool and synthetic fibres. The International Tennis Federation (ITF) sets the rules for approved balls: their size (roughly 6.5–6.9 cm in diameter), weight (about 56–59.4 g) and how high they must bounce when dropped. Within those limits, manufacturers make balls that feel quite different.
Pressurised vs pressureless
Pressurised balls
The core is filled with gas at a pressure above the surrounding air. That is what gives a fresh ball its lively bounce and the satisfying "pop" when the can is opened. They are the standard for matches and most club play.
The downside: the gas slowly escapes through the rubber from the moment the can is opened. After a few sessions, the ball becomes softer and bounces lower — a "dead" ball.
Pressureless balls
The bounce comes from a thicker, solid rubber core instead of internal pressure. They do not lose bounce over time; instead they wear out when the felt goes bald. They feel heavier and harder at first and can be tiring on the arm, but they are excellent value for ball machines, practice baskets, coaching and occasional players who would otherwise leave half a can to go flat in a cupboard.
Regular duty vs extra duty
- Extra duty balls have a thicker, more tightly woven felt that resists abrasion on hard courts. The felt fluffs up rather than wearing smooth.
- Regular duty balls have a thinner felt designed for clay and indoor courts. It picks up less clay and moisture, so the balls do not become heavy as quickly.
- Some balls are labelled all-court, a compromise between the two.
Using regular-duty balls on hard courts is not dangerous, but they will go bald faster. Extra-duty balls on clay tend to absorb clay and grow heavy and slow.
Ball speed types and altitude
The ITF also recognises balls of different speeds: Type 1 (fast), Type 2 (medium, the standard ball) and Type 3 (slow). In theory, faster balls suit slow courts and slower balls suit fast courts, balancing the game. In practice, most balls sold in shops are Type 2.
At high altitude, the thinner air makes balls fly faster and bounce higher. Some manufacturers sell high-altitude balls with lower internal pressure for clubs at altitude; at sea level they would feel flat.
Junior balls: red, orange and green
Children learn better with balls that bounce lower and travel slower, on smaller courts with shorter rackets. The ITF's progression uses colour-coded stages:
| Ball | Stage | Speed vs yellow ball | Typical court |
|---|---|---|---|
| Red (or red foam) | Stage 3 | Much slower (around 75% slower) | Short court, about 11–12 m long |
| Orange | Stage 2 | About 50% slower | Around 18 m long |
| Green | Stage 1 | About 25% slower | Full-size court |
| Yellow | Standard | — | Full-size court |
Exact ages vary by child and country, but red is common for young beginners, orange around the middle of primary school and green before moving to the yellow ball. Low-compression balls are also great for adult beginners. Matching the ball with the right racket length matters too: see our junior racket size guide.
How long do tennis balls last?
There is no fixed number, but these patterns hold:
- Competitive players often feel a difference after one or two hours of hard hitting. At professional events, balls are changed every few games for that reason.
- Club and recreational players can typically use a can for a few sessions.
- Unopened cans keep for a long time, but not forever — very old stock can feel flat on opening.
- Heat and humidity affect play: warm balls bounce higher, damp balls feel heavy.
Simple tests for a dead ball
- Squeeze it: a fresh ball is firm; a flat one squashes easily.
- Drop it from head height next to a fresh ball: the dead one bounces noticeably lower.
- Look at the felt: bald, smooth patches mean less grip on the strings and erratic flight.
Tip: flat, heavy balls make you swing harder and can aggravate a sore arm. If you have elbow or shoulder trouble, fresh pressurised balls are one of the cheapest things you can change. More in our arm-friendly setup guide.
Which balls should you buy?
- Matches and regular club play: pressurised balls, extra duty on hard courts, regular duty on clay and indoors.
- Occasional play or a ball machine: pressureless balls, or a bulk pack of practice balls.
- Children and beginners: red, orange or green balls according to level.
- High-altitude clubs: high-altitude balls.
Buying in cartons rather than single cans usually lowers the cost per ball, and many clubs and brands run recycling schemes for old balls. Your shoes also depend on the surface — see tennis shoes by surface.
Frequently asked questions
How long do tennis balls last?
Pressurised balls start losing pressure as soon as the can is opened. For casual play they are typically good for a few sessions; competitive players often notice a drop after one or two hours. Pressureless balls do not go flat but wear out as the felt becomes bald.
What is the difference between regular duty and extra duty balls?
Extra duty balls have a thicker, more durable felt designed for hard courts, which are abrasive. Regular duty balls have a thinner felt that picks up less clay and moisture, making them better suited to clay and indoor courts.
Can I bring old tennis balls back to life?
Pressurisers — sealed tubes that keep balls under pressure between sessions — can slow the loss of bounce. Once a ball is soft and the felt is worn, it is best used for practice, a ball machine, the dog or recycling programmes.
Which balls should children use?
Young children usually start with red (stage 3) balls, then progress to orange (stage 2) and green (stage 1) balls before moving on to regular yellow balls. These lower-compression balls bounce lower and slower, so children can rally with proper technique.