Chess Elo Rating Calculator
Calculate your new Elo rating after any game. Enter your rating, your opponent's rating, and the result to get expected score, rating change, performance rating, and percentile.
Game Details
New Rating
1500
Enter a game result above to calculate
Expected Score
0.500
Rating Change
+20
New Rating
1520
Perf. Rating
1900
K-Factor
40
Percentile
~50th
E = 1/(1+10^((Opp−My)/400))
ΔR = K × (S − E)
The expected score E ranges from 0 (certain loss) to 1 (certain win), with 0.5 at equal ratings. The S-curve below shows how your expected score changes as the rating gap widens. Values update automatically from Tab 1.
Rating Difference
(Your rating − Opponent's)
(Your rating − Opponent's)
0
Expected Score
0.500
Score %
50.0%
Assessment
Even Match
| Rating Diff (My−Opp) | Expected Score | Score % | Assessment |
|---|
Simulate a series of games and track your rating trajectory. Add each game result to see how your rating evolves across a session or tournament.
Add Game
Syncs with Calculator tab. Changing it resets all games.
Games
0
Net Change
—
Current Rating
—
No games added yet. Add your first game above.