I was playing with Stu's calculator, and was going to look at wood arrows.  Is there a chart that shows the conversion between spine in pounds to deflection.  Say 60-65lb = what in deflection.  I can enter the deflection in the
calculator to determine what will work, but it doesn't tell me what that is in pounds. Am I missing something?  I've ran several searches and came up empty.  Thanks in advance.

The formula is simple.  For wood, you divide the deflection into 26 to get the # spine rating.  So, dividing the weight into 26 will give you the deflection.  26 divided by 60 = .433.

REMEMBER!! you divide into 26(twenty six) to get the spine rating for 28" (TWENTY EIGHT!!)

Thanks! Would that be entered into the AMO/AMA box on Stu's calculator, or the ASTM box.  Thanks again!

That's the old AMO standard.