Fret Calculator

The placement of guitar frets is governed by a logarithmic musical scale known as the twelve-tone equal temperament system. The distance from the nut (or the zero point) to any specific fret (n) is calculated using the formula: Distance = ScaleLength * (1 - (1 / (2^(1/12)))^n). Here, the factor 2^(1/12) represents the twelfth root of two, which is the constant frequency multiplier between any two adjacent semi-tones in Western music. By raising this ratio to the power of the fret number, the calculator determines the exact fractional distance down the fingerboard from the nut to the crown of each fret.

Suppose you are building a custom electric guitar with a standard Fender-style scale length of 25.5 inches, and you need to determine the positions for the first and twelfth frets.

Step 1: Calculate the first fret (n = 1).
Using our formula: 25.5 * (1 - (1 / (2^(1/12)))^1).
The value 1 / (2^(1/12)) is approximately 0.943874.
Subtracting this from 1 gives 0.056126.
Multiplying by 25.5 yields a distance of approximately 1.431 inches (or 36.35 mm) from the nut.

Step 2: Calculate the twelfth fret (n = 12), which marks the octave.
Using our formula: 25.5 * (1 - (1 / (2^(1/12)))^12).
Raising the ratio to the 12th power simplifies the math because (1 / 2^(1/12))^12 equals 1/2, or 0.5.
Thus, 25.5 * (1 - 0.5) equals 25.5 * 0.5, which equals exactly 12.750 inches from the nut. This confirms the classic rule that the octave fret sits precisely at the halfway point of the scale length.

Measure Twice, Cut Once: Always measure cumulative distances from the nut rather than measuring individual distances between adjacent frets. Measuring each fret independently allows tiny measurement errors to accumulate, leading to severe intonation issues further up the neck.

Account for the Blade Kerf: When cutting your fret slots with a saw, ensure your saw blade's kerf width matches your fret tang width, and mark your lines with a razor knife for ultimate precision before cutting.