Due the the constraints of that darn Euclidean Geometry and conic sections, there are 6 parameters we can use to define the profile of a Fretboard –

Width at the nut

Width at some other point

Start Radius

Radius at some other point

Binding thickness at Nut

Binding thickness at some other point

(there’s actually another parameter which is thickest point but that’s not important just yet)

If we define 5 of those parameters, the 6th one pops out automatically. In my current design, I’ve chosen to have the “radius at some other point” the parameter that “pops out automatically” and that the binding thickness is constant for the whole fretboard.

As an example, for a 25.34″ scale, if you chose 1.75″ nut, 2.25″ 14th fret and a 12″ radius at the nut, you get a radius of about 19.7″ at the 14th fret.