๐ธ Fret Distance Calculator
Theoretical values based on 12-tone equal temperament. Real instruments have manufacturing tolerances.
| Fret | From nut | From previous |
|---|---|---|
| 1 | 1.431 in | 1.431 in |
| 2 | 2.782 in | 1.351 in |
| 3 | 4.057 in | 1.275 in |
| 4 | 5.261 in | 1.203 in |
| 5 | 6.397 in | 1.136 in |
| 6 | 7.469 in | 1.072 in |
| 7 | 8.481 in | 1.012 in |
| 8 | 9.436 in | 0.955 in |
| 9 | 10.338 in | 0.902 in |
| 10 | 11.189 in | 0.851 in |
| 11 | 11.992 in | 0.803 in |
| 12 | 12.750 in | 0.758 in |
| 13 | 13.466 in | 0.716 in |
| 14 | 14.141 in | 0.675 in |
| 15 | 14.779 in | 0.638 in |
| 16 | 15.380 in | 0.602 in |
| 17 | 15.948 in | 0.568 in |
| 18 | 16.484 in | 0.536 in |
| 19 | 16.990 in | 0.506 in |
| 20 | 17.468 in | 0.478 in |
| 21 | 17.919 in | 0.451 in |
| 22 | 18.344 in | 0.425 in |
| 23 | 18.746 in | 0.402 in |
| 24 | 19.125 in | 0.379 in |
Enter a guitar or bassโs scale length (the string length from nut to bridge) to calculate the distance from the nut to each fret, using the standard equal-temperament formula. Useful for instrument building, modification, or marking fretless fingerboards.
How to use
- Enter the scale length.
- Select the unit (inches or millimeters).
- Enter how many frets to calculate.
- Each fretโs distance from the nut, and from the previous fret, is listed.
How the calculation works
From a guitar or bass scale length (the string length from the nut to the bridge saddle), this tool calculates how far each fret is from the nut, using twelve-tone equal temperament. Distance from the nut to fret n = scale length ร (1 โ 1 รท 2^(nรท12)) Each fret shortens the vibrating length to about 0.9439 of the previous one (one over the twelfth root of 2), raising the pitch a semitone. So frets get closer together as you go up, and the 12th fret sits at exactly half the scale length. Choose inches or millimetres; results are in the same unit as the scale length you enter.
Worked example
Scale length 25.5 in (Fender-style guitar) Fret 1: 1.431 in Fret 12: 12.750 in (exactly half) Fret 24: 19.125 in (three quarters) Scale length 648 mm Fret 1: 36.369 mm, fret 12: 324.000 mm 34 in (long-scale bass), fret 12: 17.000 in
Things to be aware of
- Real instruments move the bridge saddle slightly back to make up for the extra tension when a string is pressed down (intonation or compensation).
- Common scale lengths: Gibson-style 24.75 in, Fender-style 25.5 in, bass 34 in, classical guitar about 650 mm.
- The traditional โrule of 18โ (dividing the remaining length by 17.817) gives almost the same values as this formula.
FAQ
What formula does this use?
Distance from the nut to fret n = scale length ร (1 - 1/2^(n/12)) โ the standard equal-temperament fret spacing formula (the exact exponential form, equivalent to the traditional "rule of 18").
Why is the 12th fret always exactly half the scale length?
The 12th fret corresponds to one octave higher, and since an octave is a 2:1 frequency ratio in equal temperament, it always lands at exactly half the scale length.
Can I use this for building a fretless bass?
Yes โ itโs useful for calculating the positions of pitch reference marking lines on a fretless fingerboard.