This app estimates your new US Chess rating after a tournament, using the official US Chess rating formulas for Regular, Quick, and Blitz time controls. The US Chess ratings calculation system is a complicated set of algorithms and processes that fill a 16-page document. This app was created because many players’ guesses at their ratings changes proved surprisingly inaccurate. Please send us any specific instances where the app fails to accurately estimate the correct scores.

Enter your current rating, number of prior rated games, your age, and the results of each game in your tournament. The app applies the US Chess rating algorithm — including K-factor, effective games, and age bonus calculations — to estimate your post-tournament rating.

This app is designed exclusively for US Chess ratings and does not calculate FIDE or any other chess rating system. Results are estimates only. Official ratings are calculated by US Chess and may differ due to additional factors, rounding, or rule changes. Always refer to your official US Chess rating for authoritative results.

This app is not affiliated with, endorsed by, or sponsored by US Chess (the United States Chess Federation). “US Chess” and related names are the property of their respective owners. This is an independent tool created to help players estimate rating changes.

This app does not collect, store, or transmit any personal information. All calculations are performed locally on your device. No user data, game results, or rating information is ever sent to any server. If playing against unrated players, US Chess’s formula uses a player’s age as a rating proxy. For this reason, you may optionally put in ages, but this information is used only in the calculation and is not recorded.

This app is built on the Expo platform. Expo may automatically collect limited diagnostic information such as crash logs and error reports to support app stability. This data is processed by Expo (a service of Expo, Inc.) and is used solely for debugging purposes. It does not include any personally identifiable information or data you enter into the app.

No user data is saved between sessions. When you close the app, all entered values are discarded.

This app does not use any third-party analytics, advertising, or tracking services beyond the Expo platform diagnostics described above.

If you have any questions about this privacy policy, please contact us.