Enter your instrument scale length and number of frets to generate exact equal-temperament fret locations.
How this fret position calculator works
This tool calculates fret placement using the modern 12-tone equal temperament system used on most guitars, basses, and fretted instruments. The scale length is the distance from the nut to the bridge saddle contact point (for practical shop work, luthiers often use the theoretical scale then apply saddle compensation later).
Distance from nut to fret n = Scale Length − (Scale Length ÷ 2n/12)
For each fret, this page provides:
- Distance from nut (where to cut the slot)
- Distance from previous fret (helpful for checking spacing)
- Remaining string length (nut-to-bridge vibrating segment after fretting at that fret)
Step-by-step: using the calculator
1) Enter your scale length
Common values include 25.5" for Fender-style guitars, 24.75" for Gibson-style guitars, and 34" for many basses. If you work in metric, choose millimeters and enter values like 648 mm or 629 mm.
2) Set the fret count
Typical fretboards run from 19 to 24 frets. The calculator supports up to 36 to cover custom builds, extended-range instruments, and niche projects.
3) Generate and transfer measurements carefully
After calculating, mark each position from the nut line with high-accuracy tools (steel ruler, digital caliper, precision marking knife). Small cumulative errors can cause major intonation issues, so double-check at key checkpoints like fret 12 and fret 24.
Common scale lengths
- Guitar (Fender style): 25.5 in (647.7 mm)
- Guitar (Gibson style): 24.75 in (628.7 mm)
- PRS-style compromise: 25 in (635 mm)
- Bass guitar: 34 in (863.6 mm)
- Short-scale bass: 30 in (762 mm)
Luthier notes for better accuracy
Measure from one reference edge
Always reference from the same nut face when marking. Avoid leapfrogging from fret to fret, since tiny errors add up quickly.
Mind kerf and centerline
Your saw kerf removes material. Make sure your marking method aligns the fret slot center exactly to the calculated line.
Compensation is separate
This calculator gives theoretical fret locations. Bridge saddle compensation adjusts intonation and is done afterward during setup.
Quick FAQ
Does this work for 7-string, 8-string, or multiscale?
Yes for standard equal-temperament single-scale instruments. For multiscale/fanned frets, calculate each string’s scale independently and map to your neutral fret geometry.
Why is the 12th fret special?
The 12th fret is exactly half the scale length in equal temperament, creating the octave. It is a good sanity check for your measurements.
Can I use this for ukulele, mandolin, or custom instruments?
Absolutely. If the instrument is fretted and based on 12-tone equal temperament, you can use the same math with the correct scale length.