Fret calculation

Brad Sarno · Post by **Brad Sarno** » 29 Mar 2002 3:35 pm

A friend built me a lap steel but it has no fret markers except an inlayed moon at fret 7 and 12 and 19. If I wanted to make a fretboard or mark the guitar in some way, what's the best way to calcualte the exact fret spacing.

Brad Sarno

Larry Beck · Post by **Larry Beck** » 29 Mar 2002 4:30 pm

There are lot's of handy dandy calulators on the internet. They are usually based on the 12th root of 2 calculation. Here's a couple:
http://www.buildyourguitar.com/resources/fretcalc/fretcalc.pdf
http://www.dougsparling.com/cgi-bin/fretcalc.cgi

chas smith · Post by **chas smith** » 29 Mar 2002 5:49 pm

Also, if you know the scale degree, whether it's tempered or just, then the reciprocal of the scale degree multiplied by the scale length (bridge to nut) is the location of that fret from the bridge.

So the 7th fret on a 24" scale in temper tuning would be: (1/(12th root of 2 to the 7th power)) X 24

The 12th root of 2 = 1.059463
The 12th root of 2 to the 7th power= 1.4983
1/ 1.4983=.6674
.6674 X 24=16.018
So the 7th fret of the (tempered 12 tone scale) on a 24" scale is 16.018 from the bridge.