FIDE rating calculator
This FIDE rating calculator works out your rating change from your results. Enter your rating, tick what applies to you so the right K is used (40, 20 or 10), and add each opponent's rating and your result. It uses the expected-score table and the 400-point rule from FIDE's Rating Regulations, and rounds as FIDE does.
Your games
- 1
Result
Enter your rating to start.
How it is calculated
- For each game the difference between the two ratings is looked up in FIDE's table to get your expected score. A difference of more than 400 points counts as 400 if you are rated below 2650.
- Your result (1, ½ or 0) minus the expected score is the game's difference. The differences are added up and multiplied by K.
- K is 40 until you have 30 rated games, and for players under 18 rated below 2300; 20 below 2400; 10 once your published rating has reached 2400, even if it drops back.
- If K times the number of games in the rating period is more than 700, K is lowered to the largest whole number that fits.
- The change for the period is rounded to a whole number, with a half rounded away from zero.
Source: FIDE Rating Regulations effective from 1 March 2024 (FIDE Handbook B.02), read on 2026-11-11. Chesspedition is not affiliated with the federation; its own published figure is the one that counts.
Questions
- What is my K-factor?
- K is 40 if you have fewer than 30 rated games, or if you are under 18 (until the end of the year of your 18th birthday) and rated below 2300. Otherwise it is 20 while your rating stays under 2400, and 10 once your published rating has reached 2400.
- What is the 400-point rule?
- If you and your opponent are more than 400 points apart, the game is rated as if the difference were exactly 400. Since 1 October 2025 this applies to players rated below 2650; from 2650 the real difference is used.
- Why does FIDE's published change sometimes differ by a point?
- FIDE rounds the total change for a whole rating period, not each tournament. If you played more than one event in the month, add all of that month's games here to get the same rounding.
- Does it work for rapid and blitz?
- Rapid and blitz have their own regulations. This calculator follows the regulations for standard ratings.
- Is there a separate calculator for AICF ratings in India?
- The All India Chess Federation's own guide to ratings describes FIDE's method and points to the FIDE handbook, and we found no separate national formula published by AICF. Use this calculator for FIDE-rated events in India.