Music · Luthiery
Guitar fret position calculator.
Enter the scale length and get the distance from the nut to every fret, so you can mark or check a fingerboard for a guitar, bass, ukulele or mandolin.
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Fret positions
Fill the form to see the result.
How far is each fret from the nut?
Measure from the nut: fret n sits at L − L / 2n/12, where L is the scale length. That follows from 12-tone equal temperament, where the ratio of the distances of two consecutive frets to the bridge is the twelfth root of two, about 1.059463. The 12th fret therefore divides the string into two exact halves.
Worked example. A 25.5 in scale: fret 1 is 1.431 in from the nut, fret 5 is 6.397 in, fret 12 is 12.750 in and fret 24 is 19.125 in (three quarters of the scale length). The gap between frets 1 and 2 is 1.351 in and shrinks to 0.379 in between frets 23 and 24.
Mark from the nut, not fret to fret. The table gives both the cumulative distance from the nut and the gap from the previous fret. Use the cumulative column when you cut slots, so rounding errors do not add up along the neck.
Saddle compensation is separate. To compensate for the increase in string tension when a string is pressed against a fret, the bridge position is adjusted slightly so the 12th fret plays exactly in tune. This tool gives the theoretical scale length positions; set the saddle position by ear and tuner on the finished instrument.
Frequently asked questions
What is the formula for fret spacing?
Distance from the nut to fret n = L - L / 2^(n/12), where L is the scale length. Each fret is 1/1.059463 (the twelfth root of two) of the previous fret-to-bridge distance.
Where is the 12th fret on a guitar?
Exactly halfway along the scale length. On a 25.5 in scale that is 12.750 in from the nut.
Does this work for bass, ukulele and mandolin?
Yes, for any fretted instrument in 12-tone equal temperament. Enter that instrument’s scale length. Instruments with non-equal-temperament frets, such as a saz, need different positions.
Why do the gaps between frets get smaller?
Each fret shortens the vibrating string by the same ratio, not the same length, so the physical gap shrinks toward the bridge.
Does this include bridge compensation?
No. It gives the theoretical positions for the scale length you enter. Compensation for string tension is set on the bridge saddle after the instrument is strung.
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