FIDE Rating Calculator
Free tool · No account needed
K = 20
standard
Games
New rating
1829+29
From 1800 on the Standard list.
- Scored
- 3 / 5
- Expected total
- 1.57
- Sum of score minus expectation
- +1.43
- Before rounding
- +28.60
- Performance rating
- 2033
How this is worked out
Each game's expected score comes from FIDE's table 8.1.2, not from the logistic curve, so the figures match the published rating list. The differences are added up and multiplied by K, then rounded to a whole number with a half going away from zero.
A rating difference wider than 400 points counts as 400 for players rated below 2650. From 2650 up the real difference is used, a change that took effect on 1 October 2025.
Runs in your browser. Nothing is uploaded.
Enter your published rating, add a row per game with your opponent’s rating and the result. This free online FIDE calculator applies the official FIDE Rating Regulations as written: the expected score for each game comes from Table 8.1.2, the development coefficient follows the rules in article 8.3.3, and the total is rounded according to article 8.3.4, alongside tournament performance rating.
How to work out your rating change
- 1.
Type in the rating you are published at. If you are still completing your first thirty rated games, or you are a junior, tick the box that applies.
- 2.
Add one row per game: the opponent’s rating, and whether you won, drew or lost.
- 3.
Read the expected score beside each row; the number in brackets is the rating difference actually used after the cap.
- 4.
The panel shows your new rating, the change, and the event’s performance rating.
What this tool does
The official table, not the formula
FIDE converts a rating difference into an expected score with a lookup table whose steps round to two decimals. Calculators that use the logistic curve instead disagree by a point or more over a long event.
The 2650 rule
On the standard list, since 1 October 2025 the 400-point cap on the rating difference applies only below 2650. Above it the real gap is used, which changes what a draw against a much weaker opponent costs. Rapid and blitz keep the cap for everyone.
Every K-factor case
Forty while you are completing your first thirty games, forty for juniors under 2300, ten once 2400 has been reached, twenty otherwise, and the ceiling that keeps K times the number of games at 700 or less.
Performance rating too
The opponents’ average plus the rating difference for your fractional score, from table 8.1.1 — the number tournament reports print.
Frequently asked questions
How does this FIDE rating calculator determine Elo changes?
For each game it takes the rating difference, reads the expected score from table 8.1.2, and subtracts it from what you actually scored. Those differences are added up across the event and multiplied by your development coefficient K. The result is rounded to a whole number, with a half rounding away from zero.
Why is the difference capped at 400 points?
To stop a single result against a far weaker or far stronger opponent from moving a rating too far. Since 1 October 2025 the cap only applies to players rated below 2650; from 2650 up the true difference is used in every case.
Is this an official FIDE calculator?
No. It implements the published FIDE Rating Regulations and Table 8.1.2 directly in your browser, matching published rating lists. The official FIDE rating list remains the ultimate authority, and your national federation may use different rules.
Can I use it for a Chess.com or Lichess rating?
Only as a rough guide. Chess.com uses the Glicko system and Lichess uses Glicko-2, where the change also depends on how settled each rating is, so the same result moves an online rating by a different amount. This calculator follows FIDE's Elo rules for over-the-board ratings.
What K-factor applies to me?
K is 40 while you are completing events totalling your first 30 rated games, and 40 for a player until the end of the year of their 18th birthday as long as their rating is under 2300. It is 10 once a published rating has reached 2400, and stays there even if the rating later drops. Otherwise it is 20.
Does this work for rapid and blitz ratings?
Yes, with the rapid or blitz list selected. The FIDE Rapid and Blitz Rating Regulations use the same probability table and the same K rules as the standard list (K = 40, 20 or 10 on the same conditions). Two things differ: the 400-point cap applies to every player, with no 2650 exception, and since 1 December 2024 a game is not rated when the players are 600 or more points apart and either is rated above 2600. The selector applies both.
Where do I get my opponents’ ratings from?
The pairing sheet or the tournament’s published start list carries them, and they are the ratings used for the calculation, not whatever the opponent is rated by the time the list is published.
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