What are the rules for a tennis ball?
Officials' detail · The court, the net, the ball and the racket · 3 of 4Checked 13 October 2026
A standard tennis ball weighs 56.0 to 59.4 grams, is 6.54 to 6.86 cm across and is yellow or white with a fabric cover. The event decides how many balls are used and when they are replaced, usually after a set number of games, because balls go soft with use.
How it works
- Mass 56.0 to 59.4 grams; diameter 6.54 to 6.86 cm for the standard types.
- The rules define fast, medium, slow and high-altitude types. The slow type is slightly larger.
- Colour: white or yellow.
- The event announces in advance the number of balls (2, 3, 4 or 6) and the ball-change policy.
- Changes come after an agreed odd number of games, with the first change two games earlier to allow for the warm-up, or at the start of a set.
- A tie-break counts as one game for ball changes, and balls are not changed at the start of a tie-break.
- A ball that breaks during a point: the point is replayed. A ball that has only gone soft: the point stands.
Tricky cases
Why does the umpire call "new balls"?
To tell the players that fresh balls are coming into play, which bounce and fly differently.
The ball felt flat after a point. Is the point replayed?
No. Only a broken ball means a replay.
Why the rule exists
Balls lose pressure and their felt wears as they are hit. Regular changes keep the bounce and speed consistent through a match.
Where it differs
| Where | What changes | Source |
|---|---|---|
| ITF rules | As above | L3; App I |
| 10 and under tennis | Slower red, orange and green balls | App I; App VIII |
From the rule book
ITF Rules of Tennis 2026, Rule 3 and Appendix I. Checked 13 October 2026. Official document: ITF Rules of Tennis (PDF).