Professional toolkit for guitar builders and luthiers. Calculate fret spacing, string tension, nut depth, and bridge compensation. Essential tools for precision instrument making.
LuthierCalc is a free set of thirteen calculators for guitar and stringed-instrument builders, repair techs and curious players. Every tool runs entirely in your browser, returns numbers to the precision a real build demands, and is backed by the same published formulas a luthier would reach for on the bench — no sign-up, no stored data.
The geometry tools cover the layout decisions that have to be exact. Fret spacing places each slot with the twelve-tone rule (distance from nut = scale − scale ÷ 2^(n/12)), so a 25.5" (647.7 mm) scale puts the first fret 36.35 mm out and the twelfth at exactly half-scale, 323.85 mm. The fretboard radius, nut spacing, fretboard template and intonation calculators round out the setup and template work, while string tension turns gauge, pitch and scale into the static pull on the neck.
The build-and-materials tools answer the questions that come before glue and clamps. Estimate air-drying time by species and thickness, predict how a fingerboard moves with shop humidity, compare body volume and weight across shape families and woods, rank tonewoods by stiffness-to-weight ratio, dial in truss-rod turns, work out pickup coil resistance, and check pickup-to-amp impedance loading. Pick a calculator below to get started — each page explains its formula, shows worked examples, and answers the questions builders ask most.
It is the mathematical constant used to divide the remaining scale length to find the position of the next fret, ensuring each semitone is perfectly in tune.
Yes. Longer scale lengths require higher tension to reach the same pitch for a given string gauge. This is why 25.5" scales feel 'snappier' than 24.75" scales.
Stretching a string to the fret increases its tension and sharpens the note. Moving the saddle back (compensation) corrects this so the fretted note stays in tune.