A new free fretting calculator has just been added to the knowledgebase here at CigarBoxGuitar.com. Simply enter in the scale length you want (in either inches or millimeters) and it will show you the distance from the nut to place each fret from the first fret to #36 (you don’t have to use all of them).
The calculator even shows you which frets to skip to end up with a diatonic (dulcimer-style) fretboard!
Click the image to the left or click here to check out the calculator tool.