ELO Rating Calculator

Calculate your FIDE ELO rating change based on your tournament results. Load opponents automatically via Chess-Results integration.

How to Calculate ELO?

Go to the calculator tool and select the FIDE ELO Calculator tab.
Enter your current FIDE ELO rating and your K-factor.
Add your opponents' ratings and game results (win, draw, loss).
You can also load opponents automatically via a Chess-Results tournament link.
Click "Calculate" to see your new ELO rating.

ELO Calculation Formula

New Rating = Old Rating + K × (Actual Score - Expected Score)

The K-factor multiplied by the difference between actual and expected scores gives the rating change.

Expected Score (E) = 1 / (1 + 10^{(Opponent - Player) / 400})

With a 400-point rating difference, the expected score is approximately 0.09 (weaker side) or 0.91 (stronger side).

K-Factor Table

Condition	K-Factor
New players (first 30 games) and under 18	K = 40
Players rated below 2400	K = 20
Players who have reached 2400	K = 10

Calculate your ELO rating change now.

Calculate ELO

Frequently Asked Questions

How is an ELO rating calculated?

The ELO rating is calculated using the formula: New Rating = Old Rating + K x (Actual Score - Expected Score). The expected score is derived statistically from the rating difference.

What is the K-factor and how is it determined?

The K-factor is a coefficient that determines the magnitude of rating changes. According to FIDE rules: K=40 for new players, K=20 for players below 2400, and K=10 for players who have reached 2400.

What does expected score mean?

The expected score predicts the outcome of a game by comparing both players' ratings. It is a value between 0 and 1, where values closer to 1 indicate a higher win expectation.