Table Tennis Rating Expectancy Calculator
Estimate the win probability between two table tennis players from their ratings using the Elo expectancy formula.
How it works
Expected win % = 1 ÷ (1 + 10^((opponent rating − your rating) ÷ 400))
Table tennis bodies such as USATT rate players on an Elo-style scale, where the rating gap between two players maps directly to an expected result. The logistic formula turns the difference into a probability: equal ratings give a coin-flip, a 200-point edge gives roughly 76%, and a 400-point edge about 91%. It is a probability of winning the match, not a prediction of the exact 11-point game scores.
Worked example
A 1600-rated player facing a 1400-rated opponent has a 200-point edge: 1 ÷ (1 + 10^((1400 − 1600) ÷ 400)) = 1 ÷ (1 + 10^(−0.5)) ≈ 0.76, about a 76% chance to win.
Sources: Wikipedia — Elo rating system
Frequently asked questions
Does a higher rating guarantee a win?
No. A 200-point favourite still loses about one match in four. Ratings describe long-run probabilities, not the outcome of any single match, which is exactly why upsets happen.
Why divide by 400?
The 400 constant sets how quickly the win probability changes with rating. It is the standard Elo scaling, chosen so that a 400-point gap corresponds to roughly a 10-to-1 favourite.
Is this the exact USATT formula?
USATT uses a points-exchange table for updating ratings, but the underlying win-expectancy is the same Elo logistic curve used here, so the probabilities line up closely.
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This calculator is for educational purposes. Double-check important results before acting on them.