Expected score
The share of the points your rating predicts against an opponent. Against an equal opponent, it is 0.50. Against an opponent rated 200 points lower, it is about 0.76, so a draw there costs you points.
Chess rating calculator
Work out your new rating after a tournament or a month of games. Pick FIDE, US Chess, or the plain Elo formula, enter your opponents’ ratings and your results, and see the change game by game.
For FIDE-rated over-the-board games. Enter one month’s games.
Players rated below 2400.
Below 2650, a rating difference above 400 counts as 400.
Games
- 1
Expected 0.40 · +12.0
- 2
Expected 0.56 · -1.2
- 3
Expected 0.32 · -6.4
- 4
Expected 0.65 · +7.0
Turn your openings into rating points
Rating points often slip away in the first ten moves. Chessmate trains each opening line on the board with spaced review, so you reach the middlegame in positions you know.
How to use the rating calculator
Choose a rating system
Pick FIDE for FIDE-rated events or US Chess for USCF events. To set your own K-factor, choose the Elo formula.
Enter your rating and settings
Use your rating from before the event or rating period. For FIDE, choose the time control and your K-factor; for US Chess, enter how many rated games you have played.
Add each game
Enter each opponent’s rating and your result. Every row shows your expected score and how many points that game is worth.
Read your new rating
The result shows your new rating, the change, your performance rating, and the numbers behind them. Your games are saved on this device.
How FIDE, US Chess, and Elo ratings are calculated
Every system compares your score with the score your rating predicts. Score more than expected and you gain points; score less and you lose them. The systems differ in how they predict the score and how far one event can move your rating.
FIDE ratings
FIDE looks up the expected score in a table and multiplies the difference from your score by K: 40, 20, or 10. Each month’s games are rated together, a gap above 400 counts as 400 for most players, and ratings start at 1400.
US Chess ratings
US Chess sets K from the games you have played and the games in the event, so newer players move faster. Strong results can earn bonus points, and players with 8 or fewer games use a special formula.
The Elo formula
The original formula: new rating = old rating + K × (score − expected score). Many clubs and tools use it with a fixed K. Lichess and Chess.com use the related Glicko systems instead.
Performance rating
The rating your results were worth in one event: your opponents’ average rating plus a value from FIDE’s table for your percentage score. Scoring 50% against a 1700 average is a 1700 performance, and 100% adds 800.
Rating calculator FAQ
How is a FIDE rating change calculated?
For each game, FIDE finds your expected score from the rating difference and multiplies K by your actual score minus that expected score. The changes for all your games in the month are added up and rounded. At 1650 with K 20, a win against a 1720 player is worth 20 × (1 − 0.40) = +12.
Which K-factor does FIDE use?
K is 40 until you have played 30 rated games, and for players under 18 rated below 2300, until the end of the year they turn 18. Otherwise, K is 20 below 2400 and 10 once you have reached 2400, even if your rating drops later. If K times your games in one month would be more than 700, K is lowered.
How do I get my first FIDE rating?
Play at least five games against FIDE-rated opponents. They can come from several events within 26 months. FIDE averages your opponents’ ratings, adding two imaginary opponents rated 1800 that you drew with, and adjusts that average for your score. A first rating is at most 2200 and must be at least 1400. This calculator is for players who already have a rating.
Why can’t I enter a FIDE rating below 1400?
1400 is the lowest FIDE rating. Players who drop below it are listed as unrated, so a game against an opponent below 1400 does not change your FIDE rating. For lower ratings, use the Elo formula.
How accurate is the US Chess calculation?
It follows the published US Chess formulas with your opponents’ ratings from before the event. The official calculation runs a second time with your opponents’ new ratings from the event and applies personal rating floors, so the official result can differ by a few points.
What rating does a new US Chess player start with?
Without another rating, US Chess starts from your age: 50 × age for players aged 2 to 26, so 750 at 15, and 1300 for players over 26. A FIDE or Canadian (CFC) rating is converted instead when you have one. Enter 0 prior games and use that starting rating as your rating.
What is a performance rating?
The rating your results were worth in one event. This calculator uses FIDE’s method: your opponents’ average rating plus a value from FIDE’s table for your percentage score. It does not change your rating, but FIDE uses it for title norms.
Can I convert a Lichess or Chess.com rating?
Not with a formula. Lichess and Chess.com use Glicko rating systems with their own player pools, so their numbers do not line up with FIDE or US Chess ratings. Their changes also depend on how settled your rating is, so the Elo formula here gives only a rough idea for online games.
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