I have a table in a data grid the columns are bound to the columns...

SQFT QTY WIDTH LENGTH

i also have added into the datagrid an unbound column called Yeild%

what i'm trying to do is the following formula

SQFT / (QTY * (width * length / 144) and have the result return the answer in the unbound yield column for that row represented as a percentage

So if SQFT = 178 QTY = 2 Width = 144 Length = 102 answer would be 0.87 (rounded)

so this would be 87%

Also if there's a better method any help would be appreciated