CALC 1 Home Documentation Home Contact

CALC 1 Elo Expected Score Formula Calculator

Calculates the expected score of a player with an Elo rating Ra against a player with an Elo rating Rb.




Formula: 1/(1+10^(-(Ra-Rb)/400))

Ra: Rating of player a.

Rb: Rating of player b.

Example 1

For a player with a rating of 1600, what is their expected score against a player rated 1450?


Value Keystrokes Display Description
1600 STO Ra 1,600.0000 Stores the Ra value.
1450 STO Rb 1,450.0000 Stores the Rb value.
  Ea 0.7034 Calculates Ea.

Example 2

Calculate the rating of an opponent where the expected score of player a is 0.6.

These keystrokes assume the values from example 1.


Value Keystrokes Display Description
.6 STO Ea 0.6000 Stores the Ea value.
  Rb 1,529.5635 Calculates the Rb value.


Elo Rating System- Wikipedia