http://www.primecomputing.com/formula.htm
a = (((Comp/Att) * 100) -30) / 20
b = ((TDs/Att) * 100) / 5
c = (9.5 - ((Int/Att) * 100)) / 4
d = ((Yards/Att) - 3) / 4
a, b, c and d can not be greater than 2.375 or less than zero.
QB Rating = (a + b + c + d) / .06
For Manning
a=(((336/497 *100)-30/20 = (67.60563-30)/20=37.60563/20=1.88028169
b=(49/497) * 100)/5=9.859155/5=1.971831
c=(9.5-((Int/att) *100))/4=9.5-((10/497)*100)/4)=(9.5-2.012072)/4=7.487928/4=1.871982
d=(4557/497) -3/4=(9.169014-3)/4=6.169014/4=1.542254
QB =(1.880282+1.911831+1.871982+1.542254)/.06=7.266348/.06=121.1058
For Brady
a=(398/578*100)-30/20=(68.85813-30)/20=38.85813/20=1.942907
b=(50/578)*100/5=8.650519/5=1.730104
c=(9.5-(Int/att) *100))/4=9.5-((8/578)*100/4=(9.5-1.384083)/4=8.115917/4=2.028979
d=(4806/578)-3)/4=(8.314879-3)/4=5.3134879/4=1.32872
QB rating=(1.942907+1.730101+2.028979+1.32872)/.06=7.030709/.06=117.1785