How to calculate passer rating

Almost nobody in the world knows exactly what the QB Passer Rating is and more importantly how to calculate it. We just know a large number is Peyton Manning and a low number is Rex Grossman. I'm a little embarrassed I never looked up the significance of the stat, considering I use the QB rating as an analysis of past and present quarterbacks. Finally, I decided to hit up wikipedia and find out what the rating actually tells you about a quarterback

It is actually a well thought out statistical analysis of quarterback efficiency based on 4 main attributes. They are completion percentage, yards per attempt, TD per attempt, and interceptoins per attempt. Each of these categories are set to an upper and lower limit with increasing diminishing returns for the upper limits. If you do reach the upper limits in each category, such as 12.5 yards/att and no interceptions, then you will have a perfect rating of 158.3

If you want to calculate it yourself, just employ this easy to use formula.