CALCULATOR
Neck Relief Calculator
Find the relief, action and truss rod adjustment for a given string set.
Suggested reliefmm
Relief in inches
Relief now mm
Action at the 12th
String load
Saddle height
Saddle change
Nut height
Fretboard radius
Action bands
Measured at the 12th fret, bass side, for a steel-string acoustic:
LOW under 1.5 mmMEDIUM 1.5 – 2.8 mmHIGH over 2.8 mm
Relief—
Action at 12—
Relief target = the instrument’s reference relief × (your load ÷ its reference load)
Truss turns = Δrelief ÷ (0.15 mm per quarter turn × 4)
Saddle height = 2 × (action − relief at mid-span) − nut height
Action at a fret = a straight line from nut to saddle, plus the relief curve
Truss turns = Δrelief ÷ (0.15 mm per quarter turn × 4)
Saddle height = 2 × (action − relief at mid-span) − nut height
Action at a fret = a straight line from nut to saddle, plus the relief curve
How to read thisRelief targets come from string tension and neck length: heavier strings and longer scales pull more bow into a neck and need more relief to stay clear. The figures are estimates built on standard approximations — check them against your own instrument before you make a decision that matters.
Educational tool. Nothing you type here leaves your browser. This is a reference calculation, not a measurement of your instrument, and it is not a substitute for the manufacturer’s specifications.