Battle.net Ladder Rating Calculator:

The Battle.net Ladder Rating system uses the same system as that of competitive chess, meaning that the amount of rating a player gains/loses after a game depends on the difference between his own rating and that of his opponent. Confused? The Battle.net Ladder Rating Calculator is designed to help. All you need to do is type in your own rating and that of your opponent, and it will tell you how much rating you'll have if you win, or if you lose.

We also have a more advanced dos based application by Numbed that will calculate your final rating for any number of players. This is downloadable here:

Battle.net Rating Calculator (15kb)

Using the Calculator
Most of the calculator is fairly self-explanatory, with exception of the K Value. This value stands for the development coefficient, and signifies that maximum amount of rating a player can gain or lose in a given game. Different values of K are assigned to different players:

• K=50 for new players
• K=30 for players who have played 30 or more ladder games
• K=20 for players who have attained a rating of 2400 or higher

In the field where it asks for your K Value, simply type in the value that applies to you.

Through the calculations, the calculator will use the opponent ratings in descending order. For example, if you select 2 as 'Number of Players', it'll only use the top most rating as the rating of your opponent and ignore the rating fields for Opponent 2 and 3.

Once done, press calculate or the return key to obtain your result.