Tennis match calculator
Move how many points in 100 each player wins on their own serve and pick the format. The chance of winning the match, a service game, a set and a tie-break updates at once.
A 59.9%B 40.1%
best of 3 sets, 7-point tie-breaksIf A wins 2 more points in every 100 on serve (66% instead of 64%), the match chance goes from 59.9% to 69.1%.
81.3%A holds a service game
77.6%B holds a service game
56.7%A wins a set
53.3%A wins a 7-point tie-break
What one serve point is worth
A wins more or fewer points in every 100 on serve; B stays at 62%.
| Change | A on serve | A wins the match |
|---|---|---|
| −5 | 59% | 35.0% |
| −4 | 60% | 39.9% |
| −3 | 61% | 44.9% |
| −2 | 62% | 50.0% |
| −1 | 63% | 55.0% |
| as now | 64% | 59.9% |
| +1 | 65% | 64.7% |
| +2 | 66% | 69.1% |
| +3 | 67% | 73.2% |
| +4 | 68% | 77.0% |
| +5 | 69% | 80.5% |
How the match ends, in sets
2–032.1%
2–127.8%
1–221.3%
0–218.8%
Score in sets, A first. On average the match lasts 25.3 games.
The example above
How the math is built
- PointEach player wins their serve points with a fixed chance, and no point depends on the one before.
- GameFirst to four points with a two-point lead. From deuce a player needs two in a row.
- SetFirst to 6 games with a two-game lead. At 6 all a tie-break to 7 points is played.
- Tie-breakOne player serves the first point, then two points each in turn. In the final set of the Grand Slams the tie-break goes to 10.
- MatchBest of 3 sets on the tour; best of 5 in the men’s main draw of the Grand Slams.
Sources
- itftennis.com /media/7221/2026-rules-of-tennis-english.pdf · checked Nov 2, 2026
- itftennis.com /media/5986/grand-slam-rulebook-2026-f2.pdf · checked Nov 2, 2026
Keep going
- TennisWhich Argentines play tennis today and tomorrow in Argentine time, the ATP and WTA rankings, the Grand Slams in Argentine time and the ATP Finals.
- ATP rankingThe latest ATP ranking: the top 100 with points and places moved, and every Argentine in the top 150 with the points to the place above.
- WTA rankingThe latest WTA ranking: the top 100 with points and places moved, and every Argentine in the top 150 with the points to the place above.
Questions
What percentage do I enter?
The points a player wins when serving, out of all the points they served. Match and season statistics show it. The numbers above are just an example.
Does it matter who serves first?
Not for winning a set, a tie-break or the match: the math is the same whoever starts. Only the number of games played moves a little.
Why is best of 5 kinder to the better player?
More sets have to be won, so one bad set weighs less. In the example A goes from 59.9% in best of 3 to 62.4% in best of 5. It is the same idea as in playoff series.
What does the 10-point tie-break change?
A longer tie-break gives the better server a bit more room. In the example A wins the 7-point one 53.3% of the time and the 10-point one 53.9%.