The International Tennis Federation (ITF) World Tennis Number is a global tennis rating for all players, regardless of age, ability or gender. The USTA, along with over 135 other international governing bodies to-date, has adopted the ITF World Tennis Number.
The ITF World Tennis Number does not replace NTRP ratings or USTA rankings.
The International Tennis Federation (ITF) is introducing a series of improvements to the World Tennis Number (WTN) to support the long-term sustainability of the system and ensure even greater accuracy for the growing global player community. These improvements will be introduced the week of August 10, 2026 and are based on feedback from players, coaches, providers and national associations.
For more information on these enhancements, please click here.
Below is a collection of questions and answers that provide an overview of the rating system and technical details.
General
What is the ITF World Tennis Number?
The ITF World Tennis Number (WTN) provides a global standard for players. It is a 40-1 scale, with 40 being a beginner player and 1 being an elite professional. This scale is for all players, regardless of age, gender, or ability. Players have separate WTN for singles and doubles.
What is Tennis ID?
Tennis ID is a unique identifier allocated by the International Tennis Federation (ITF) automatically and free of charge to allow a player to be identified in multiple different WTN databases and to have their results connected, creating an accurate global number.
How do I get an ITF World Tennis Number?
Participation in USTA and ITF events will result in a WTN rating. Players need match results in order to generate an initial rating. Initial WTN ratings may be at a lower “Confidence Level” until more match results are recorded. Green ball and Yellow ball results are credited towards a player's WTN as long as all players with a match are at least 9 years old. Players who are 7- and 8-years old who have earned their way from Orange ball into Green ball can also have a rating once they've played a Green ball match.
A High School team conference or state tournament held through USTA would count towards their ITF World Tennis Number.
What are the benefits of the World Tennis Number?
- Game zONe — Easily identify players at your level for closer matches, more fun, and more improvement
- Player Development — Statistics to track your progress and help improve your game
- Future Seeding, Selection, and Flighting by WTN in USTA Tournaments and Level-Based Tournaments
- International system — Players from all over the world use the WTN
- WTN is used in ITF tournament selection
- A tool for college coaches to evaluate prospective student-athletes worldwide and used for selection and seeding in college tennis events
-
Track favorite players, friends, professionals, local competition, team comparisons
How will WTN be used in the United States?
Here are a few ways the WTN is being used in the United States:
- WTN Match Play and WTN Tournaments
- Selection and seeding in USTA section and national junior tournaments
- Selection and seeding in select USTA section and national adult tournaments
- A tool for college coaches to evaluate prospective student-athletes and selection/seeding into college/open tournaments
- ITF junior and pro acceptance
-
Select Junior Team Tennis criteria
When did the USTA start to use WTN?
In 2022, the USTA began using the WTN across the United States.
Where can I find my WTN and WTNs of other players?
You can access your WTN and WTNs of other players by signing into your account on usta.com and viewing player profiles or on worldtennisnumber.com.
What information is displayed on a player's WTN profile?
A WTN profile includes the player's name, gender, nationality, ITF WTN, and age information. The age information displayed for a player varies as described below:
- For players under 14, the site will display as 'Under 14'
- 14+ to 19 years old, display "Born in YEAR"
- For 20+, ages are shown in the following bandings:
- If the age is 20 to 30, displays as '20 - 30'
- If the age is 31 to 40, displays as '31 - 40'
- If the age is 41 - 50, displays as '41 - 50'
- If the age is over 50, displays as '50+'
Do college coaches use WTN?
WTN is the official exclusive rating of college tennis. It is a key tool college coaches use to assess players worldwide. Most every nation where a college coach is recruiting is providing their national association results to WTN. The significance of having many nations providing data is that it allows for an apples-to-apples comparison amongst players of various parts of the world. More data = more accuracy.
What cost is associated with WTN?
WTN is free. There are no costs associated with WTN for players or providers.
Technical
How is WTN calculated?
The WTN algorithm operates using a rolling three-year rating window. Older results gradually drop out of the calculation. The more data used, the more accurate the rating. Pre-match ratings of both players are used by the algorithm to project the outcome of the match. Your WTN changes based on your match score compared to the projection. Current results carry more weight than older results. While set outcomes remain the dominant component of the WTN, game-level results are also considered. By recognizing performance within sets, the system better reflects relative playing strength.
When are WTNs updated?
The WTN Rating is published each Wednesday at approximately 3:00 am EST.
Why is WTN updated weekly?
WTN is updated weekly due to the vast amount of data and the frequency with which the data is contributed. There are over 135 national associations providing data every day. With this amount of data, a weekly release of updated WTNs is most sensible. From a developmental standpoint, weekly updates are plenty of data points. For these reasons, the ITF feels that weekly is the best interval on which to update WTNs.
What is Game zONe?
Game zONe is the range of player ratings where you will achieve the most competitive matches. This range will include players with slightly higher and lower WTNs than your own. Gaining match results within your Game zONe is the fastest way to improve your WTN.
How is Game zONe determined?
Game zONe is your range of opponents where either player would have a probability of winning the match of between 35%–65%.
What happens if I play someone outside my Game zONe?
Matches against players both inside and outside your Game zONe count toward your rating. However, matches within your Game zONe generally have greater relevance because they represent more competitive matchups.
Will Playing Opponents Far Above or Below my Level Harm my Rating?
Not necessarily. The system considers the expected outcome of the match. Playing stronger or weaker opponents will not negatively impact your rating if your performance aligns with expectations.
What is the Confidence Level?
The Confidence Level is a measure of how accurate your rating is. A blue checkmark to the right of your WTN indicates a high level of confidence in your rating’s accuracy. A gray checkmark to the right of your WTN indicates a lower level of confidence in your rating’s accuracy. In order to increase your Confidence Level, you’ll need to add more match results to your WTN profile.
How is Confidence Level calculated?
Confidence Level uses many statistics. Prominent metrics include total matches, how current the matches are, total opponents, and confidence level of opponents.
What is the relationship between the WTN rating and its Confidence Level?
The Confidence Level can have a significant impact on a player’s rating. Faced with the same set of results, two players with the same rating, but with different Confidence Levels, will experience different rating updates. The player with a lower Confidence Level will see his/her rating fluctuate more.
The factors that make the Confidence Level change are stated in the previous section.
How is my Confidence Level determined?
As a guideline, the Confidence Level of your ITF World Tennis Number will fall if you are inactive for two months. If you compete in 5+ matches in a two-month period, your Confidence Level will remain higher. The more matches you play, the more confident your rating will be. The highest Confidence Level occurs at 30 recorded matches or more a year.
Are weightings applied for levels for types of tournaments?
Yes, all tournaments and competition types tagged independently but the pertinent factor for updating the rating is the opposing player’s rating.
Will younger players see changes to their ratings over time?
Yes. The system includes a small adjustment to reflect natural player development, particularly among junior players. This helps ensure ratings remain aligned with improving physical and technical ability.
What is the effect of a long time off court?
If you do not compete for over a year, a small and gradual adjustment may be applied to reflect the impact of inactivity. Gradual adjustments help maintain fair competition and improve the accuracy of ratings.
Players who do not take part in competition for a significant period, will have a lower confidence level when they return to play. The algorithm will react more strongly to the results as it tries to calibrate the player’s rating after a long absence of data.
My WTN is wrong. What can I do?
If you see an incorrect match result on your WTN, please contact the event director to have this reviewed. Your WTN will automatically update the following week if a change was made. If it has been more than two weeks since the completion of an event and you find results are missing, please send an email to customercare@usta.com with these details:
• Player’s Name
• Player’s USTA Number
• A link to the event page
• Division
I won my match. Why did my rating go down?
Your match results, despite winning, may not have met or exceeded the algorithm’s projection.
I lost my match. Why did my rating go up?
Your match results, despite losing, may have exceeded the algorithm’s projection.
What match results will count towards my WTN?
Any tournament or league match that is recorded on a USTA platform counts towards your WTN. The result will count toward WTN regardless of whether or not WTN was used to select, seed or flight players. Results in countries outside of the United States that provide results to the WTN will also count.
How can I improve my WTN?
You’ll need to consistently outperform the algorithm’s expected result.
How do defaults affect my rating?
Defaults are not factored into a player’s WTN.
What happens if a match is not completed, for example due to retirement?
The algorithm considers available score data while maintaining fairness and integrity within the rating calculation.
Is there any advantage to stopping a match early to protect my rating?
No. The system is designed to discourage this behaviour. Completing matches and competing for every game provides the most accurate reflection of performance.
How are tiebreaks treated in the rating?
Tiebreaks are included as part of the overall match result. However, they are not treated in the same way as a full set because they are played over a shorter format.
To learn more about the ITF World Tennis Number, visit https://www.worldtennisnumber.com/eng/faq