Action or string height on a guitar, is the distance from the frets to the underside of the strings, or the height that a string must be depressed before it meets the fret. It's an important adjustment for optimal playability.

The adjustment of string height at the first fret is done by filling in or deepening the nut slots. The height at the 12th fret is adjusted by raising or lowering the saddle. Because the different diameters that the strings vibrate the action need to increases from the nut to the last frets, and from the treble to the bass strings.

Note! The truss rod should be properly adjusted before setting the action.

Gibson and Epiphone

Gibson and Epiphone1)
Electric Guitars Acoustic Guitars
String Height String height
1st fret- treble side 1/64“ 0.4 mm 1st fret- treble side 1/64” 0.4 mm
1st fret- bass side 2/64“ 0.8 mm 1st fret- bass side 2/64” 0.8 mm
12th fret- treble side 3/64“ 1.2 mm 12th fret - treble side 5/64” 2 mm
12th fret - bass side 5/64“ 2 mm 12th fret- bass side 7/64” 2.8 mm

Fender and Squier

Fender and Squier guitars2)
Instrument String Height Bass Side String Height Treble Side
Electric Guitars 4/64” (1.6 mm) 4/64”
Basses 6/64” (2.4 mm) 5/64” (2 mm)

See also