Elo Rating Calculator
Rating change after gamesRuns locally · nothing uploaded
Games played
Opponent ratingResultExpected
0.36
0.57
0.43
New rating
1,603
Rating change
+2.8
Score / expected
1.5 / 1.36
Performance
1,633
Under FIDE rules, rating differences over 400 are counted as 400.
Also works as:elo calculatorfide rating calculatorchess rating changeexpected scoreperformance rating
How it works
Formula
E = 1 ÷ (1 + 10^((Ropp − R) ÷ 400))Change = K × (score − expected)Worked example
Given: Rating 1600, K = 20: win vs 1700, draw vs 1550, loss vs 1650
- Expected 0.360 + 0.571 + 0.429 = 1.360.
- Score 1.5; change = 20 × 0.140 ≈ +2.8.
Result: New rating ≈ 1603; performance ≈ 1633.
Sources
- FIDE Rating Regulations
- Elo AE. The Rating of Chessplayers, Past and Present. 1978.
How to use
- 1Enter your rating and choose a K-factor.
- 2Add each game's opponent rating and result.
- 3Read the expected score, change and performance.
FAQ
What is the Elo formula?
E = 1 ÷ (1 + 10^((Ropp − R) ÷ 400)); new rating = R + K × (score − E).
Related tools
Chess ClockGame clock for chess, Go and xiangqiTournament Bracket GeneratorRound robin and knockout bracketsPercentage CalculatorPercent of, ratio and percent changeChina University Fitness Test CalculatorScore China's student fitness testChina School Fitness Test CalculatorGrades 1–12 fitness test scoreRace Time PredictorPredict race times from one result