Chess Elo Rating Change Calculator
Calculate expected score and rating change based on Elo ratings and game results
About this calculator
The Chess Elo Rating Change Calculator helps chess players determine how their rating will change after games based on the Elo rating system. By inputting your current rating, your opponent's rating, and the game result (win, loss, or draw), the calculator computes your expected score and the exact rating points gained or lost. This tool is essential for tournament players, chess coaches, and anyone wanting to track their rating progression and understand how different opponents affect their ranking.
How to use
Enter your current Elo rating and your opponent's Elo rating in the respective fields. Select the game result (win, draw, or loss) from the dropdown menu. Click calculate to see your expected score probability and the exact rating change that will be applied to your current rating.
Frequently asked questions
How is the Elo rating change calculated?
The change uses the formula: New Rating = Old Rating + K-factor × (Actual Score - Expected Score), where expected score depends on rating difference.
What K-factor does the calculator use?
Most calculations use K=32 for players under 2100, K=24 for 2100-2400, and K=16 for players rated above 2400.
What does expected score mean in chess?
Expected score is the probability of winning based on rating difference, where 1.0 = certain win, 0.5 = draw, and 0.0 = certain loss.