Chess Win Probability Calculator
What are your chances of winning a chess game against a specific opponent? Based on the Elo rating system, calculate win, draw, and loss probabilities from rating difference.
Win Probability
Elo Expected Score Formula
Expected Score = 1 / (1 + 10^((Opponent Rating - Your Rating) / 400))
This formula, developed by physicist Arpad Elo, gives your expected score (where 1 = win, 0.5 = draw, 0 = loss).
Rating difference examples:
- 0 points difference: 50% win rate
- 100 points advantage: ~64% expected score
- 200 points advantage: ~76% expected score
- 400 points advantage: ~91% expected score
Draws are most common at small rating differences and rare at large gaps.