Back to Ratings.
Enter all required information as indicated, then click on the Calculate button to see a player’s new rating after a tournament. If a player has not played fifty games in his or her career, their rating will change by a greater amount; this is taken into account if you specify the player by name and not by rating.
Players may earn feedback bonus points for playing opponents who earned acceleration bonus points: this tool does not perform this calculation.
You may also want to use the tsh tournament management program, which includes the code libraries used to compute official ratings.