I don't use an offset myself, but do fletch my daughter's arrows that way. When I first got my Bitz I put the shaft in and the clamp on and adjusted it as much as I thought reasonable for the shoot through rest she is using. I realize that doesn't answer the question, but not sure you really need to know the exact degree of offset. Put as much on as you can shoot with your rest so you maximize the spin rate. If you shoot a drop away, I would switch to helical anyway to improve broad head flight.