NFL Passer Rating Simplified...

The Passer or Quarterback Rating Formula provides a means of comparing passing performances from one game to the next or one season to the next. It is a system used to statistically rate quarterbacks. Obviously, statistics do not reflect the leadership abilities of the quarterback and takes nothing into consideration other than PASSING the football.

There are four categories used to obtain the Passer Rating:

  • Percentage of completions per attempt
  • Average yards gained per attempt
  • Percentage of touchdown passes per attempt
  • Percentage of interceptions per attempt

The maximum a quarterback can receive in any of the above categories is 2.375, and the lowest is 0.

If the value is above 2.375, 2.375 is awarded.

If the value is below 0, 0 is awarded!

Percentage of completions per attempt

(Pct. Completions – 30) x 0.05
For example, to earn a 2.375, the completion percentage would have to be 77.5.
(77.5 – 30) x 0.05 = 2.375

Average yards gained per attempt

((Passing Yards Gained / Pass Attempts) – 3) x 0.25 OR   (Passing Yards Per Attempt – 3) x 0.25
For example, to earn a 2.375, a passer would have to average 12.5 yards passing per attempt.
(12.5 – 3) x 0.25 = 2.375

Percentage of touchdown passes per attempt

(Touchdowns / Pass Attempts) x 0.2
For example, to earn a 2.375, the touchdown percentage would have to be 11.875%.
11.875 x 0.2 = 2.375

Percentage of interceptions per attempt

2.375 – ( (Interceptions / Pass Attempts) x 0.25)
For example, to earn 2.375 in percentage of interceptions, no interceptions can be thrown!

The sum of the points from all four categories is then converted into a scale of 100 by dividing it by 6 and multiplying by 100.

Example ...

On Thursday, September 19, 2013 – the Kansas City Chiefs defeated the Philadelphia Eagles 26 – 16.
Alex Smith completed 22 of 35 passes for 273 yards, threw no touchdowns or interceptions.
His Passer Rating would be calculated as follows:

He completed 63% of his passes ( 22 / 35 = 63% ) and earns 1.65 points
( 63 – 30 ) x 0.05 = 1.65

On average, he threw for 7.8 yards per attempt (273 / 35 = 7.8) and earns 1.2 points
( 7.8 – 3 ) x 0.25 = 1.20

He threw for no touchdowns and earns zero points
( 0 / 35 ) x 0.2 = 0

He threw no interceptions and earns maximum number of points
2.375 - ( ( 0 / 35 ) x 0.25 ) = 2.375

Thus: The Passer Rating earned for this game is 87.08 !

( 1.65 + 1.20 + 0 + 2.375) = 5.225

5.225 / 6 = 0.8708

0.8708 x 100 = 87.08