I'm wondering if someone could me speed my rating of past races with the use of a speadsheet.

The formula is:

CR=Class Rating of the race
BM=Beatem Margin
WT=Weight Carried
LW=Limit Weight

CR-BM*1.5+WT-LW

An example follows 65-(3.5*1.5)+56.5-53=63.25 rounded to 63.5

Mad Gambler