Elo rating update
Elo rating update: use your rating, opponent rating, actual score. Review the formula, worked example and calculation steps.
Inputs
Use the units shown—
Enter your values and select Calculate.
Formula & explanation
E = 1/(1+10^((opponent−rating)/400)); new = rating+K(score−E)
Variables & units
- Your rating
- Numeric value · minimum 0, maximum 1000000000000
- Opponent rating
- Numeric value · minimum 0, maximum 1000000000000
- Actual score
- win=1, draw=0.5, loss=0 · minimum 0, maximum 1
- K factor
- Numeric value · minimum 0, maximum 1000000000000
Worked example
Use the example inputs to explore this model; the solution shows each supplied quantity.
Assumptions
Single-game classic logistic Elo with supplied K; federation-specific adjustments are excluded.
Formula version 1.0.0. JavaScript floating-point arithmetic applies. Results display up to 6 decimal places; stored values retain available precision. Use the units shown.
Practice with an example
Use the default input values to find the answer. The reset icon restores those values.
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