Elo Calculator
Find updated Elo ratings after a game.
The Elo system updates ratings based on results versus the expected outcome.
The math behind it
Expected score = 1 ÷ (1 + 10^((B−A)/400)). New rating = old + K·(actual − expected). Beating a higher-rated opponent gains more.
Worked example
1600 beats 1500 (K 32) → gains ~12.2 points.
FAQ
What is the K-factor?
How fast ratings change — higher K means bigger swings per game.