ORIGINAL: vertical grimmace
... I have found 1/8'' equals around 1 degree, on most models.
An incidence meter is a very necessary investment IMO and I prefer the Robart offering. Not cheap really, ...
Actually .016 inch or 1/64 inch shim per inch of chord equals 1 degree.
A very inexpensive incidence meter can be quiclkley made from a $3.99 angle indicator from Harbor Freight. Or a few bucks more for a digital angle meter.