NFL Analytics

NFL Passer Rating Simplified

The formula that statistically rates every quarterback in the league

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. Statistics do not reflect leadership ability and take nothing into consideration other than passing the football.

Maximum Possible Rating

158.3

The Four Categories

Every passer rating is built from four ingredients. Each is capped at 2.375 on the high end and floored at 0 on the low end. Values above 2.375 are awarded 2.375; values below 0 are awarded 0.

Percentage of Completions per Attempt

( Completion % − 30 ) × 0.05

Example

To earn a 2.375, the completion percentage would have to be 77.5.

( 77.5 − 30 ) × 0.05 = 2.375

Average Yards Gained per Attempt

( ( Passing Yards / Attempts ) − 3 ) × 0.25

Example

To earn a 2.375, a passer would have to average 12.5 yards per attempt.

( 12.5 − 3 ) × 0.25 = 2.375

Percentage of Touchdown Passes per Attempt

( Touchdowns / Attempts ) × 0.2

Example

To earn a 2.375, the touchdown percentage would have to be 11.875%.

11.875 × 0.2 = 2.375

Percentage of Interceptions per Attempt

2.375 − ( ( Interceptions / Attempts ) × 0.25 )

Example

To earn a 2.375 in this category, no interceptions can be thrown!

Putting It Together

Add the four scaled values, divide the total by 6, then multiply by 100. That number is the passer rating.

Rating = ( C + Y + TD + INT ) / 6 × 100

Worked 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, with no touchdowns or interceptions.

Completion % — 63% ( 22 / 35 )

( 63 − 30 ) × 0.051.65

Yards per attempt — 7.8 ( 273 / 35 )

( 7.8 − 3 ) × 0.251.20

Touchdown % — 0 TDs

( 0 / 35 ) × 0.20.00

Interception % — 0 INTs

2.375 − ( ( 0 / 35 ) × 0.25 )2.375

Sum = 1.65 + 1.20 + 0 + 2.375 = 5.225

5.225 / 6 = 0.8708

0.8708 × 100 = 87.08

Final Passer Rating

87.08