Free chess tools
These free chess tools do the arithmetic that rating lists, norm rules and clocks rely on. Each one shows its formula, a worked example and the source of every FIDE number, and each runs in your browser, so you can try as many inputs as you like.
Chess rating calculator
Work out how a FIDE rating changes after a run of games, with the Handbook table and the textbook Elo formula side by side.
Open the toolUS Chess (USCF) rating estimator
Estimate how a US Chess rating changes after an event, with the published formula, effective games, K and the bonus shown.
Open the toolChess performance rating calculator
Turn a score against a field of opponents into a performance rating, from a list of games or from totals.
Open the toolChess time control calculator
See whether a base time and increment counts as bullet, blitz, rapid or classical on Lichess and under FIDE rules.
Open the tool
How the tools are built
Every FIDE value comes from a transcription of the current FIDE Handbook that records the chapter and clause, the edition date and the day it was checked. The same code runs in the tool, in its worked examples and in the text version of its page, so the numbers cannot differ between them.
Numbers tell you where you are, a lesson shows you what to do next
The first lesson reviews your games, reads your level and ends with a written study plan.