Does US Chess rate each round separately?

No. The event is rated as a whole. The round-by-round column recomputes that formula on the games so far. The last row is the event estimate.

When does the bonus apply?

When the raw gain clears 10 times the square root of the games (three-round events use 4), and you did not face an opponent too often.

Free tool · April 2026 specification

USCF Rating Estimator and Calculator (2026 Formula, Round by Round)

Enter the pre-event rating, the prior games, and each result. The estimate uses K = 800 / (effective games + games in the event), adds a bonus only when it is earned, and stops at the rating floor.

Your rating going in

The event is rated as a whole. Each round below updates the estimate.

Pre-event ratingPublished regular ratingGames already ratedMore than 25 means established

Rounds

ROUND 1
Opponent rating
Result
ROUND 2
Opponent rating
Result
Who did you play?
ROUND 3
Opponent rating
Result
Who did you play?
ROUND 4
Opponent rating
Result
Who did you play?

Repeating an opponent can turn the bonus off. Leave each round as a different opponent unless you really played the same person again.

Floor, dual-rated events, and matches

Peak established ratingLeave blank if you do not need a floor. Used only to figure the rating floor.Dual-rated time control (G/30 to G/65). Changes K only for a regular rating over 2200.This is a match. Bonus stays off and the change is capped at 50 points.

What this implements

The math follows the US Chess rating specification dated April 6, 2026, including the bonus multiplier of 10 that took effect January 1, 2025. Players with 8 or fewer prior games use the special formula. A match is capped at 50 points and does not take the bonus or an automatic floor.

It is an estimate. The office stores decimals, rates the whole field together, and can apply manual adjustments. Use it to understand a wall chart, not to argue a posted rating.

Also see the performance rating calculator, the FIDE calculator, and how a rating works.