What the Tennis Rating (UTR-Style) Calculator does
This calculator estimates a single-match tennis rating on the same 1.0-16.5 scale made familiar by the Universal Tennis Rating (UTR). Instead of looking only at who won, it rewards how many games you took from a rated opponent, so a close loss to a strong player and a lopsided win over a weaker one both land where they belong. The output is a performance rating: roughly where your play in that one match sits on the UTR scale.
How to use it
Enter your opponent's UTR rating (a number from 1.0 to 16.5), the total number of games you won across the match, and the number of games your opponent won. Then calculate. The main figure is your estimated match rating; the table also shows how far above or below your opponent you played and the share of games you won.
The formula explained
First we measure the share of games you won, P:
$$P = \frac{w}{w + L}$$Here w is the games you won and L is the games your opponent won. We then turn that share into a rating offset from your opponent and add it to their rating R_o:
$$R = R_o + S \cdot \log_{10}\left(\frac{P}{1 - P}\right)$$This is the standard Elo-style performance-rating inversion: an even 50% game share (P = 0.5) returns your opponent's exact rating, and winning a larger share pushes you above it. The scale constant S = 3.32 is a transparent calibration chosen so that winning about twice as many games as you lose places you roughly 1.0 point above your opponent. The estimate is clamped to the valid 1.0-16.5 UTR range. UTR's official algorithm is proprietary and blends many recent matches with reliability and recency weighting; this tool is a transparent, opponent-adjusted approximation for a single result.
Worked example
Suppose you play an opponent rated 8.0 and win 12 games while losing 6. Your game share is P = 12 / 18 = 0.667, so P / (1 - P) = 2. The base-10 log of 2 is about 0.301, and 3.32 times 0.301 is about 1.00. Your match rating is R = 8.0 + 1.00 = 9.0 - one full point above your opponent, reflecting a clear but not lopsided win.
Frequently asked questions
Is this the official UTR number? No. UTR's real algorithm is proprietary and weighs up to your last 30 matches with reliability and recency factors. This calculator is a transparent single-match approximation on the same 1.0-16.5 scale, not an official rating.
Why does the score matter and not just who won? Because the share of games you win reflects how competitive the match was. Beating a player 6-0 6-0 signals a much larger skill gap than edging them 7-6 7-6, and the game-based formula captures that difference.
What happens if I won every single game? A clean sweep gives no information about how much better you are, so the math is capped to avoid an infinite offset and the estimate stays within the 1.0-16.5 range. Play closer matches against varied opponents for a more precise picture.
