Elo calculator
The calculator uses the same formula as chessmail. It is preset with the values that actually apply here. You can change the K-factor and the D-value to see how other rating systems calculate.
Expected score
The share of points you win on average against this opponent.
| Result | Diff. | New |
|---|---|---|
| Win | ||
| Draw | ||
| Loss |
Rating change depending on the rating of the opponent
Hover over the graph to read the values. A click adopts the rating of the opponent.
How it is calculated
The rating difference gives the expected score, the share of points a player wins on average against this opponent. The rating change is the difference between the actual result and that expected score, multiplied by the K-factor.
The K-factor decides how much a single game counts. A high K-factor lets the rating react quickly to new results, a low one smooths it out. New members therefore play with a higher K-factor, so they reach their real playing strength quickly.
The D-value defines which rating difference counts as a clear gap in class. With a D-value of 400, a player who is 400 points ahead wins about ten out of eleven games in theory. A smaller D-value makes the curves in the graph steeper, so the favourite counts as clearly superior even with a small lead.
chessmail rounds to whole points, exactly like this calculator. Only games that are played as rated games count.