lluciano:
Work on a 3 : 1 basis, in other words 27 feet of upwards elevation will mean an extra 9 yards of distance hit.
But it is not consistent, as #18 at Oakmont can demonstrate.
With high trajectory clubs yes ... with medium high trajectory or medium, you will need to add more ... about half the height I found when using them back in 2009. Downhill, dividing the drop by 4 and subtracting the result from your distance is close on most holes. Knowing the holes that play shorter or longer than the stated distance helps also, but that will come from experience and by asking other, more experienced players.