Elo rating calculator
Your new Elo rating after a game, and your chances of winning.
How it works
Expected score = 1 / (1 + 10^((opponent − you) / 400)). New rating = rating + K × (result − expected).
Results are for guidance only and do not replace professional advice.
Worked example
With the default values:
- Your rating1450
- Opponent's rating1600
- ResultWin
- K-factor20 (standard)
you get:
- New rating1,464 (+14.1)
- Expected score29.7 %
- If you win+14.1
- If you draw+4.1
Frequently asked questions
How does the “Elo rating calculator” tool work?
Expected score = 1 / (1 + 10^((opponent − you) / 400)). New rating = rating + K × (result − expected).
What do I need to enter?
Just fill in: your rating, opponent's rating, result, k-factor. The result updates as you type.
Can you give an example?
Your rating: 1450; Opponent's rating: 1600; Result: Win; K-factor: 20 (standard) → New rating: 1,464 (+14.1); Expected score: 29.7 %.
Is this calculator free, and is my data private?
Yes. HOD Calc is completely free with no sign-up. The calculation runs in your browser: nothing you type is sent or stored.