Quick answer
Win percentage = matches won ÷ (won + lost) × 100. 23 wins and 7 losses is 23 ÷ 30 = 76.67% over 30 matches.
Enter matches won and lost. The calculator returns the win percentage and matches played. Use this tennis win percentage calculator to check your own figures.
Related tools: Winning Percentage Calculator: Winning percentage from wins, losses and ties. On-Base Percentage Calculator: Baseball on-base percentage. Slugging Percentage Calculator: Baseball slugging percentage from hit types and at-bats.
How to use the Tennis Win Percentage Calculator
- Enter matches won (a whole number, 0 or more).
- Enter matches lost (a whole number, 0 or more).
- Press Calculate to see the result, and use Reset to start again.
| Input | What to enter | Allowed values |
|---|---|---|
| Matches won | A whole number | ≥ 0 |
| Matches lost | A whole number | ≥ 0 |
Formula and method
Formula
win % = won ÷ (won + lost) × 100
IEEE-754 double precision; shown to the decimals indicated.
Counts completed matches only. Informational estimate, not medical advice. Talk to a qualified health professional about your own situation.
Worked examples
These examples are verified: each one is an automated test case that the live calculator must reproduce exactly.
Example 1
Inputs: Matches won = 23; Matches lost = 7.
| Result | Value |
|---|---|
| Win percentage | 76.67% |
| Matches played | 30 |
Example 2
Inputs: Matches won = 40; Matches lost = 40.
| Result | Value |
|---|---|
| Win percentage | 50% |
| Matches played | 80 |
Example 3
Inputs: Matches won = 3; Matches lost = 9.
| Result | Value |
|---|---|
| Win percentage | 25% |
| Matches played | 12 |
The first line is the headline result (win percentage). Below it the tennis Win Percentage Calculator lists matches played, which describe the same case from other angles. IEEE-754 double precision; shown to the decimals indicated.
Reading a record
A 76.67% record means winning about three of every four matches. Compare with opponents of similar level: win rates in club tennis depend heavily on the standard of the opposition.
What it ignores
Win percentage doesn't weigh the strength of opponents or the score. A player with a 60% record against strong opponents may be better than one with 80% against weaker ones. At least one match is needed.
How the result changes with matches won
Holding every other input at the first worked example, this table changes only matches won. It shows how sensitive the answer is to that one value; each row was produced by running this calculator.
| Matches won | Win percentage | Matches played |
|---|---|---|
| 12 | 63.16% | 19 |
| 23 | 76.67% | 30 |
| 46 | 86.79% | 53 |
| 92 | 92.93% | 99 |
What happens with invalid input
These messages are produced by the calculator itself, so you know what to fix.
- Matches won: entering "0" shows "Enter at least one match." beside that field and no result.
Choosing between the Tennis Win Percentage Calculator and similar calculators
Each row shows what a related calculator on this site asks for and what it returns, so you can pick the one that matches your question.
| Calculator | You enter | It returns |
|---|---|---|
| [Winning Percentage Calculator](/fitness/winning-percentage/) | wins, losses and ties count as | Winning percentage |
| [On-Base Percentage Calculator](/fitness/on-base-percentage-calculator/) | hits, walks and hit by pitch | On-base percentage |
| [Slugging Percentage Calculator](/fitness/slugging-percentage-calculator/) | singles, doubles and triples | Slugging percentage |
| [Basketball Shooting Percentage Calculator](/fitness/basketball-shooting-percentage-calculator/) | field goals made and field goals attempted | Field goal % |
| [Golf Handicap Calculator](/fitness/golf-handicap-calculator/) | adjusted gross scores, course rating for each score and slope rating for each score | Handicap Index |
Background: fitness estimates
Fitness formulas are estimates whose accuracy depends on the input. One-rep-max formulas such as Epley and Brzycki give different answers, and predictions from hard sets of a few repetitions are better than from sets of ten or more. Age-based maximum heart rate formulas can be off by 10 to 30 beats a minute for an individual; Tanaka's 208 − 0.7 × age is generally preferred to 220 − age but is still an estimate.
Pace models built from a race result assume a maximal effort and work best for distances from about 5 km to the marathon. Use the output as a guide, not a prescription.
Assumptions and limitations
- At least one match
- Not a diagnosis
Estimates from formulas describe averages. They are not a training or medical prescription; check with a qualified professional before changing your exercise or diet.
If a required value is empty, not a number, or outside its allowed range, the form marks that field with a message and shows no result instead of a misleading number. The automated checks deliberately try invalid entries for matches won to confirm this.
Frequently asked questions
What is a good win rate?
Above 50% means more wins than losses.
How many matches give a reliable figure?
At least 20 to 30 matches; with fewer, one result moves the percentage a lot.
Does it count retirements?
Enter them as you choose.
What does the Tennis Win Percentage Calculator calculate?
Match win percentage. It returns Win percentage and Matches played.
What formula does the Tennis Win Percentage Calculator use?
win % = won ÷ (won + lost) × 100. Counts completed matches only.
What do I need to enter in the tennis Win Percentage Calculator?
You enter Matches won and Matches lost.
How is the result rounded or limited?
IEEE-754 double precision; shown to the decimals indicated. At least one match.
What are the limits of this calculator?
At least one match. Not a diagnosis.
What is an example of a tennis Win Percentage result?
With matches won 23 and matches lost 7, the win percentage is 76.67%.
Can I rely on this calculator for a decision?
Estimates from formulas describe averages. They are not a training or medical prescription; check with a qualified professional before changing your exercise or diet. For this calculator in particular: At least one match.
Related calculators
- Winning Percentage Calculator — Winning percentage from wins, losses and ties.
- On-Base Percentage Calculator — Baseball on-base percentage.
- Slugging Percentage Calculator — Baseball slugging percentage from hit types and at-bats.
- Basketball Shooting Percentage Calculator — Field-goal, effective field-goal and three-point percentages.
- Golf Handicap Calculator — World Handicap System index from your recent scores.
- Batting Strike Rate Calculator — Cricket batting strike rate.
Sources
- Common definition used on this page. No single authoritative standard defines it, so the exact formula is stated in the formula section above
Content last reviewed 2026-11-04. Formulas and worked examples are checked by automated tests against independently computed values.