Chess Rating Tools & Calculators

Compare two Lichess players on one chart, track your progress and current form, and calculate anything about chess ratings — free, in your browser, no login.

Lichess tools Live data

Real numbers from the public Lichess API, for any player.

Rating calculators

The math behind the numbers, following the FIDE handbook.

Guides

Short reads on how chess ratings actually work.

How these tools work

The Elo system turns the rating difference between two players into an expected score, and after each game your rating moves in proportion to the gap between your actual result and that expectation — scaled by your K-factor (40 for new players, 20 standard, 10 once you have reached 2400).

The formulas follow the FIDE handbook. Lichess and Chess.com use their own Glicko-based systems, so ratings across sites are not directly comparable — the conversion calculator gives an approximate mapping. The live tools read public data straight from the Lichess API in your browser; nothing is stored.

Frequently asked questions

How many Elo points do I gain for winning a game?

Against an equal opponent with K = 20, a win gains 10 points. Beating a much stronger player can gain nearly the full K; beating a much weaker one gains close to zero. Use the Elo change calculator for the exact number.

Are Lichess and Chess.com ratings the same as FIDE ratings?

No — each platform has its own rating system and player pool, and online ratings are typically higher than FIDE for the same player. The conversion calculator gives an approximate mapping.

What is a performance rating?

An estimate of how strongly you played in one event, computed from your opponents' average rating and your score. Title norms (IM, GM) are based on it.