Here's How To Calculate The NFL Passer Rating

GREEN BAY, WI — In a 2019 week-seven game against the Oakland Raiders, Green Bay Packer quarterback Aaron Rodgers earned what is called a "perfect" passer rating of 158.3.

In the Oct. 20 game, Rodgers riddled the Raiders defense, attempting 31 passes and completing 25 of them. He threw for 429 yards and threw five touchdown passes.

Rodgers' feat came in a 42-24 rout of the Raiders at Lambeau Field. He's the fourth quarterback to accomplish the feat this year after Dallas Cowboy quarterback Dak Prescott and Baltimore Raven quarterback Lamar Jackson completed the feat on Sept. 8. Houston Texan signal-caller Deshaun Watson did it on Oct. 6 against the Atlanta Falcons.

In the NFL sense, throwing for a "perfect" passer rating is the isn't the football equivalent of throwing a no-hitter in baseball or rolling a 300 game in bowling. The NFL passer rating more the stuff of a math class than it is getting major-league hitters out, or knocking down all the bowling pins.

The NFL passer rating has been around since 1971 when the league wanted to come up with a metric that would weigh a quarterback's performance based on more than victories, touchdowns or completion percentage. It was officially adopted in 1973.

The NFL passer rating takes four separate equations, then puts the results of those equations into another equation to arrive at the final number.

Here's how to do it:

You're going to do four separate calculations. Each calculation will be input into a final, decisive calculation that will lead you to the final number.

First, some math terms:

Dividend is the number you get when you divide something.

Product is the number you get when you multiply something.

Difference is the number you get when you subtract something.

Sum is the number you get when you add something.

Step One:

Take a quarterback's completions and divide it by his attempts. Subtract 0.3 from the dividend. Take the difference and multiply it by five.

Step Two

Take a quarterback's passing yardage and divide it by his attempts. Take the dividend and subtract three. Take the difference and multiply it by 0.25.

Step Three

Take a quarterback's touchdowns and divide it by his attempts. Take the dividend and multiply it by 20.

Step Four

Take a quarterback's interceptions and divide it by his attempts. Multiply that dividend by 25. Take the product and subtract it from 2.375.

Step Four-A

If the result of any calculation in steps one through four is greater than 2.375, it is changed to 2.375. If the result is negative, it is changed to zero.

Step Five

Take the results from steps one through four, add them together, and divide them by six. Take the dividend and multiply it by 100.

There. Now you have your quarterback rating. If you don't want to go through the mathematical gymnastics, you can always just use the Pro Football Reference NFL Passer Rating Calculator.