FIDE rating calculator
Enter your FIDE rating, your K-factor and the rating of each opponent you played. The calculator applies the FIDE Elo rules, including the 400-point cap, to show your expected score, the change from each game and your new rating.
Rated below 2400
Rating change
+14
New rating 1614
- Score
- 1.5 / 2
- Expected score
- 0.81
- Exact change
- +13.77
| Opponent | Expected | Change |
|---|---|---|
| 1800 | 0.24 | +15.2 |
| 1550 | 0.57 | -1.4 |
How the FIDE rating formula works
Your expected score against an opponent is E = 1 / (1 + 10^((opponent rating − your rating) / 400)), with the difference limited to 400 points. After the game your rating moves by K × (S − E), where S is 1 for a win, 0.5 for a draw and 0 for a loss.
Example with K = 20: a 1600 player beating an 1800 player had an expected score of 0.24, so the win is worth 20 × (1 − 0.24) ≈ +15 points. A draw would bring about +5 and a loss about −5.
Choosing your K-factor
- K = 40: until you complete 30 rated games, and for players under 18 rated below 2300.
- K = 20: while your rating stays below 2400.
- K = 10: once you have reached a published rating of 2400, even if you drop below it later.
Frequently asked questions
- How is a FIDE rating change calculated?
- For each game, FIDE computes your expected score from the rating difference, then multiplies the gap between your actual and expected score by your K-factor. The changes of all games in the rating period are added up and rounded to give your new rating.
- Which K-factor should I use?
- K = 40 until you have completed 30 rated games, and while you are under 18 with a rating below 2300. K = 20 while your rating stays below 2400. K = 10 once you have reached a published rating of 2400.
- Why is the rating difference capped at 400 points?
- FIDE counts any rating difference larger than 400 points as 400. Against a much weaker opponent you therefore risk a little more than the raw difference would suggest, and gain a little more against a much stronger one.
- Is this the same as my Chess.com or Lichess rating?
- No. Chess.com and Lichess use Glicko systems with their own player pools. This calculator follows the FIDE Elo rules for over-the-board rated games.
Check real ratings
Need an opponent's rating? Look up any FIDE player or browse the top players of each federation. To understand what the number means, read how the chess Elo rating works.