Fret Position Calculator
Calculate exact fret distances from the nut for any scale length.
| Fret | Distance from Nut | Spacing from Previous |
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This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
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Request a ToolHow to Use the Fret Position Calculator
This calculator uses the standard equal temperament formula to find the exact distance from the nut to each fret on any scale length instrument.
- Select a preset or enter a custom scale length. Common lengths include 25.5 inches for Fender-style guitars, 24.75 inches for Gibson-style, 34 inches for standard bass. You can enter any decimal value for custom or vintage instruments.
- Set the number of frets. Most guitars have 21 to 24 frets. Bass guitars typically have 20 to 24. You can calculate up to 36 frets.
- Read the table. Each row shows the fret number, total distance from the nut in inches, and the spacing between that fret and the previous one. Spacing gets smaller as you go up the neck.
- Copy all to export the full fret chart for a luthier or CNC router file.
About Fret Placement
Fret positions in equal temperament follow the "rule of 18" (precisely 17.817). Each fret is placed at a distance equal to the remaining string length divided by 17.817. The exact formula is: distance = scale length - scale length / 2^(fret/12). This ensures each fret raises the pitch by exactly one equal-tempered semitone.
Scale length is measured from the nut to the saddle. When building or repairing an instrument, the fret slots are cut in the fingerboard before it is glued to the neck, so accuracy matters at the thousandths of an inch level. A slot even slightly misplaced causes intonation problems that no saddle adjustment can fully correct.
Frequently Asked Questions
What is scale length and why does it matter?
Scale length is the vibrating length of an open string, measured from the nut to the bridge saddle. Longer scales produce higher string tension at the same pitch, resulting in a brighter, tighter tone. Shorter scales feel easier to play because string tension is lower. A 25.5-inch Stratocaster feels stiffer than a 24.75-inch Les Paul strung with the same gauge strings tuned to the same pitch.
What is the rule of 18 in guitar building?
The rule of 18 is a historical approximation where each fret is placed by dividing the remaining string length by 18. The precise number is 17.817, derived from the twelfth root of 2 (2^(1/12) = 1.05946...). Using 18 instead of 17.817 causes small intonation errors that compound up the neck, making the octave at the 12th fret slightly flat. Modern CNC-routed fingerboards use the exact formula.
How does a multi-scale or fanned fret guitar work?
A multi-scale guitar uses different scale lengths for different strings, typically longer for the bass strings and shorter for the treble strings. This optimizes tension and tone across the full range of the instrument. The frets are angled or fanned to accommodate the different lengths. Each string's fret positions are calculated independently using its own scale length, using the same formula shown in this calculator.
Why does my 12th fret not intonate correctly?
Intonation problems at the 12th fret usually come from saddle position, not fret placement. When you fret a note, the string stretches slightly, which sharpens the pitch. The saddle is set slightly back from the theoretical scale length to compensate. If the open 12th harmonic is in tune but the fretted 12th is sharp, move the saddle back. If it is flat, move it forward. Nut height also affects intonation in the lower frets.