About Chess Rating Tools
What this is
Free, unofficial calculators for estimating chess rating changes under FIDE and CFC regulations. Enter your current rating, add game results, and see your projected new rating instantly — no sign-up, no account, no data stored.
Accuracy
Calculations follow the official FIDE Rating Regulations (effective March 2024) and CFC Rating Regulations. The FIDE calculator includes the 2650+ Classical exception (October 2025) and the faster time-control amendment (January 2026).
Results are estimates. Official ratings are calculated by FIDE and CFC from full tournament data submitted by arbiters — this tool cannot account for provisional ratings, initial rating establishment, or performance rating norms.
Last updated
April 2026. Rules updated to reflect FIDE 2026 regulations.
Privacy
No personal data is collected or stored. Google Analytics is used to measure page visits with IP anonymization enabled. See the Privacy Policy for details.
Contact
Found a bug or a regulation that's out of date? Open an issue on GitHub.