USCF Rating Change Calculator
Enter your rating, your opponents' ratings, and your results to instantly estimate your new US Chess rating — using the official 2020 Glickman-Doan formula.
Most players can leave this blank. The formula caps the effective game count at ~15 for your rating, so once you've played that many regular games the exact number doesn't affect the result. Only fill this in if you have fewer than ~25 regular rated games on record — for example, if you just started playing in USCF events.
Based on the official US Chess Rating System (Glickman & Doan, 2020). Results are estimates — official ratings are calculated by US Chess after the TD submits the event.
How the USCF rating formula works
US Chess uses a system designed by statistician Mark Glickman, updated in 2020. After each tournament, your rating change is calculated as K × (your score − your expected score), plus a performance bonus if you significantly outperform expectations.
Your expected score is the sum of your win probabilities against each opponent, based on the rating difference between you. Beat a player rated 400 points above you and you've dramatically exceeded expectations; beat someone 400 points below you and the gain is small.
Why your K-factor is probably higher than 32
The old fixed K-factors (32, 24, 16) are gone. The current formula sets K = 800 ÷ (N′ + games played this event), where N′ is your “effective game count” — a number that caps based on your rating, not just how many games you've played. A player rated 1200 has an effective game count capped around 14 regardless of whether they've played 50 or 500 games, giving them a K around 45–55 rather than 32. This means lower-rated players' ratings can move more quickly to reflect their true strength.
The performance bonus
When you significantly outperform your expected score, USCF adds a bonus on top of the normal K × (S − E) calculation. The bonus formula is max(0, K × (S − E) − 14√rounds) — it only triggers when your over-performance is large enough to clear the threshold. The multiplier was raised to 14 in 2017 to better reward strong tournament performances.
Why estimates differ from official ratings
USCF calculates ratings in two passes. The first pass updates every player's rating based on pre-event opponent ratings. The second pass reruns the calculation using the first-pass updated ratings — so your final rating depends on how your opponents did against everyone else in the tournament, not just you.
This calculator defaults to a one-pass estimate. To tighten the estimate in real time during a tournament, use the “Track this opponent's other results” feature under each round — enter what your opponents scored in their other games and the calculator will approximate the second pass.
Further reading
New to USCF ratings? Our guide to how USCF ratings work covers the concepts in plain language. For the full technical specification, see the US Chess Rating System document (Glickman & Doan, 2020).