Fret Position Calculator

Each fret raises pitch by the same proportional amount — one equal-tempered semitone — and because pitch and string length relate exponentially rather than linearly, an equal pitch change near the bridge requires a smaller physical distance than the same pitch change near the nut. This is a direct consequence of the twelfth-root-of-two formula, not an approximation or design choice.

Equal temperament places every fret at the mathematically exact position for perfectly even semitone spacing, which is the universal standard for conventional fretted instruments. True temperament applies small millimeter-level corrections to specific frets to improve how chords and certain intervals sound in tune in practice, a refinement associated with specialty true-tempered fretboards rather than standard guitar construction.

Scale length is the multiplier in front of the entire fret-position formula, so every fret's distance from the nut scales up or down proportionally with it. A Gibson-style 24.75-inch scale and a Fender-style 25.5-inch scale place every corresponding fret at a different absolute distance, even though the proportional spacing pattern relative to the nut and bridge stays the same.

Pressing a string down onto a fret stretches it slightly, which sharpens the pitch beyond what the fret's geometric position alone would produce — a small but audible effect, especially on wound or heavier-gauge strings. Adding a bit of extra length at the saddle end compensates for that stretch so the fretted note lands back in tune rather than consistently sharp.

The same twelfth-root-of-two formula applies regardless of instrument, since it's derived purely from equal-tempered pitch relationships rather than anything specific to guitar. The only inputs that change for a bass are the scale length, which is typically longer than a standard guitar's, and potentially a larger string compensation value to account for its thicker strings.