Elo Calculator — Expected Score & Rating Change
The logistic Elo model turns the rating difference into expected score E.
| Result | Rating change | New rating |
|---|---|---|
| Win | +12.8 | 1,512.8 |
| Draw | +2.8 | 1,502.8 |
| Loss | -7.2 | 1,492.8 |
How it works
The logistic Elo model turns the rating difference into expected score E. After one game, the change is K × (S − E), where S is 1 for a win, 0.5 for a draw and 0 for a loss.
Expected score equals win probability only in a no-draw model. With draws it is P(win) + 0.5 × P(draw). This generic model does not reproduce every federation’s tables, caps, rounding or provisional-rating rules.
Related calculators
How the Elo Calculator — Expected Score & Rating Change works
The logistic Elo model turns the rating difference into expected score E. After one game, the change is K × (S − E), where S is 1 for a win, 0.5 for a draw and 0 for a loss.
Equal ratings and the K-factor
At equal ratings, expected score is 50%. With K = 20, a win adds 10 points, a draw changes nothing and a loss subtracts 10. A larger K increases all changes without changing expected score. For betting prices, use Odds Converter; an Elo expectation alone does not determine a fair price in a game with draws.
Expected score equals win probability only in a no-draw model. With draws it is P(win) + 0.5 × P(draw). This generic model does not reproduce every federation’s tables, caps, rounding or provisional-rating rules.
FAQ
Can Elo give separate win, draw and loss probabilities?expand_more
A rating difference alone gives one expected-score value. Separate win and draw probabilities require another model or data. This calculator reports expected score explicitly.