Elo Rating Calculator

Want to find out what your new rating will be after a tournament match or wonder how your rating would change if you – hypothetically – beat the world chess champion? Then you should try our Elo rating calculator which is approximately the same as the FIDE one. For more details please have a look at our Elo Rating System article.

Change in Rating
Your New Rating
Opponent's New Rating
Player A:
Player B:

Please use with Caution as the accuracy of the Calculator has not been verified. We do not recommend using it in the evaluation of official ratings.

How to use the calculator

Using the calculator is pretty straight-forward and except for the K-factor will not need much of an explanation. You simply plug your own current rating as well as your opponent's one in the first two text boxes, set the K-factor and the game result. The options for the results are shown in typical chess notation: 1 - 0 means a win for White, ½ - ½ stands for a draw and 0 - 1 is a loss for the player with the white pieces. That leaves us with the K-factor which requires a bit, but not much, of explaining.

The Elo rating system is a relative one and adjusts the player's grading according to his or her performance compared to other players. Performance is derived from the game results and the strength of the opponents. Based on the current players' ratings, the Elo system assigns an expected score to each player. If the expected score differs from the achieved one in say a tournament, the system adjusts for this discrepancy. The K-factor is used as a weighting and sets how strongly the adjustment should be carried out. In other words, a high K-factor magnifies the adjustments and is thus ideal for new players in the system to determine their playing strength quickly, whereas a lower value is used for professional, high-graded players. FIDE refers to the K-factor as development coefficient.

What value should you use? Since our Elo-Calculator follows the one on FIDE, we suggest using the values according to the following table:

K = 40For a new player in the rating's pool until he or she finishes at least 30 games.
Also used for any player under the age of 18, as long as their rating remains below the 2300 mark.
K = 20For any player under a 2400 rating and with at least 30 games played.
Also used for RAPID and BLITZ ratings of players.
K = 10Once a player's rating reaches 2400 or above and the K-factor will remain at this level, even if the rating drops below 2400.
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