Have You Ever Wondered How The QB Rating Is Calculated?

Passer rating (known as passing efficiency or pass efficiency in NCAA Football) is a measure of the performance of Quarterbacks or any other passers . There are at least two formulas currently in use: one officially used by the NFL , and one used in NCAA. Passer rating is calculated using each quarterback's completion percentage, passing yardage, Touchdowns and Interceptions.
NCAA
Passer rating, known formally in college football as pass efficiency, is based on player performances. The NCAA passing efficiency formula is far simpler than the NFL formula, as it lacks limits on the four components:
Passer Rating (NCAA)
(8.4xyards)+(330xtouchdowns)+(100xcompletions)-(200xinterceptions)/number of attempts
The NCAA passer rating has an upper limit of 1,261.6 (every attempt is a 99-yard completion for touchdown), and a lower limit of -731.6 (every attempt is completed, but results in a 99-yard loss). A passer who throws only interceptions will have a -200 rating, as would a passer who only throws completed passes losing an average of 35 yards.
NFL
The calculation of the NFL quarterback rating involves more steps than the NCAA formula. In order to establish a maximum value for an NFL player's passer rating, a separate calculation needs to be completed involving each of the following four categories: Completion Percentage, Average Yards Per Attempt, Percentage of Touchdown Passes, and Percentage of Interceptions. If the result in any category is less than 0, the given result should be 0. If the result in any category is greater than 2.375, the given result should be 2.375. This makes the maximum possible quarterback rating for the NFL 158.3. A perfect rating requires at least a 77.5% completion rate, at least 12.5 yards per attempt, a touchdown on at least 11.875% of attempts, and no interceptions.
a=((comp/attx100)-30)x.05
b=(yards/att-3)x.25
c=(TD/att)x20
d=2.375-(int/attx25)
Then use the above calculations to complete the passer rating. I hope you now have a better understanding of how some look at the position.