Fretboard
When building a guitar neck, it is important that the frets are placed correctly.
As the length of the vibrating string is halved, the frequency doubles, and we hear a sound one octave higher than the open string.
There are 12 notes in an octave(including sharps & flats) and the formula to break the octave up into 12 pieces is to divide the length by
If you input the length of your guitar neck, this will let you know the distances from the bridge to the fret for each note.