Enter both ratings and the result to see the expected score and the new rating.
Your expected score against an opponent is
E = 1 / (1 + 10^((opponent − you) / 400)). Equal ratings give 0.5; being 400 points
higher gives about 0.92.
Your new rating is new = you + K × (result − E), where the result is
1 for a win, 0.5 for a draw, and 0 for a loss. The K-factor controls how fast
ratings move — higher for new players, lower for established ones.
Want the deeper version (and why 88chess uses Glicko-2)? Read how chess ratings work, or play a rated game free and watch your rating move.