air cowboy - as MB says, I think you have your terminology a little confused?
poldeck has given you the MAX drift which always occurs at 90 degrees off ie ALL ACROSS
For less than 90, use the 'analogue watch factor' for simplicity. Treat minutes around the face as angles off, so 15 degrees off is 15 minutes which is a quarter of the face AND a quarter of the MAX drift. 30 off is half and so on. It will work perfectly for all the flying you do. Yes, I know it does not work past 60 degrees off, but who cares? Then you use the 'poldeck value' and you will not go wrong.
Now, if you have a digital watch.........................................