Elo Rating Calculator
Calculate your new Elo rating after any match.
Enter your rating, opponent's rating, result (win/draw/loss), and K-factor to see your exact rating change.
The Elo rating system, developed by physicist Arpad Elo in the 1960s, is a method for calculating the relative skill levels of players in competitive games. It is used in chess, video games, sports leagues, and many online platforms.
Expected score formula: Expected Score (A) = 1 ÷ (1 + 10^((Rating_B − Rating_A) / 400))
This gives the probability that Player A will win (1 = win, 0.5 = draw, 0 = loss).
Rating update formula: New Rating = Old Rating + K × (Actual Score − Expected Score)
Where:
- Actual Score: 1 for win, 0.5 for draw, 0 for loss
- K-factor: controls how quickly ratings change
K-factor values in chess (FIDE standard):
- K = 40 for new players (first 30 games)
- K = 20 for established players (under 2400)
- K = 10 for top players (2400+)
Worked example: Player A (rated 1500) beats Player B (rated 1700). Expected Score (A) = 1 ÷ (1 + 10^((1700−1500)/400)) = 1 ÷ (1 + 10^0.5) = 1 ÷ 4.162 = 0.240
Rating Change (A) = 20 × (1 − 0.240) = 20 × 0.760 = +15.2 points New Rating (A) = 1500 + 15 = 1515 New Rating (B) = 1700 − 15 = 1685
Rating benchmarks (chess):
- Below 1000: Beginner
- 1000–1400: Intermediate club player
- 1400–1800: Strong club player
- 1800–2200: Expert / candidate master
- 2200–2400: FIDE Master
- 2500+: Grandmaster territory
- Magnus Carlsen peak: 2882