How Is Your NTRP Rating Actually Calculated?
Your NTRP rating is calculated by comparing an expected match result to your actual score. Before each match the system uses both players' hidden ratings to predict the outcome, then measures how far the real game score landed from that prediction. Doing better than expected raises your rating, doing worse lowers it, and the size of the move depends on opponent strength and game margin rather than the win or loss alone.
The expected result comes first
Every NTRP calculation starts before a ball is hit. The system looks at the two players' current hidden ratings and sets an expected score for the match. A higher rated player is expected to win by a wider margin; two evenly rated players are expected to split games closely. This expectation is the benchmark your real performance is measured against.
Because the expectation is built from ratings rather than names or seedings, the same final score can move two different players in opposite directions. What matters is whether you exceeded or fell short of what the numbers predicted for you specifically.
Actual score versus expectation
After the match the system compares the games you actually won to the games it expected you to win. Beat the expectation and your hidden dynamic rating ticks up. Fall short and it ticks down. The rating is carried to two decimals, for example 3.62, and is recalculated after every match you play.
This is why a win does not guarantee a rating increase. If you were expected to win 6-1, 6-1 and only won 6-4, 6-4, you underperformed and your rating can still fall slightly even though you took the match. The reverse holds too: a respectable loss against a much stronger opponent can lift your rating, because you did better than the prediction even without winning.
What the algorithm does not reveal
The exact NTRP formula is proprietary and the USTA does not publish it. The general mechanism above is well understood, but the precise weighting of margin and opponent strength is not public. The dynamic rating itself is also kept private so players cannot reverse engineer it and target a specific number.
Only the year-end rating, rounded to the nearest half point, is published, and those year-end ratings drop in early December. Each level is a 0.50 wide band, with the level number marking the top: a 3.5 covers 3.01 to 3.50, and a 4.0 covers 3.51 to 4.00. Your published level is simply your hidden rating slotted into one of those bands. The work of estimating the hidden number from your match scores is exactly what this site's estimator is built to do.
Frequently asked questions
Does winning always raise my NTRP rating?
No. A win raises your rating only if you performed at or above what the system expected. Winning by a smaller margin than predicted against a weaker opponent can still lower your rating.
Is the NTRP formula published?
No. The algorithm is proprietary and the USTA does not release it. The general mechanism of expected versus actual results is known, but the exact math is not public.
Unofficial. NTRP and USTA are trademarks of the United States Tennis Association; this site is independent and not affiliated with the USTA. Your official rating lives in TennisLink.