Guitar Fret Frequency Calculator

Guitar Fret Frequencies and Equal Temperament

Every fret on a guitar raises the pitch by exactly one semitone in the 12-tone equal temperament (12-TET) system. The frequency of each semitone is a fixed mathematical ratio above the previous one.

The Fundamental Formula

f_n = f_0 × 2^(n/12)

Where:

• f_0 = open string frequency (Hz)
• n = fret number (0 = open, 1 = first fret, etc.)
• 2^(1/12) ≈ 1.05946, the semitone ratio

Each fret multiplies the frequency by approximately 1.0595. Every 12 frets exactly doubles the frequency (one octave up).

Standard Guitar Tuning (E Standard)

Common Alternate Tunings

Open G catches people out. The tuning is named for the chord it sounds, not for the lowest string: in D G D G B D the 6th string is a D and it is the fifth string that carries the G at 98.00 Hz.

The 12th Fret Rule

The 12th fret always plays exactly one octave above the open string, double the frequency. The 7th fret plays a perfect 5th (ratio 3:2, close to 2^(7/12) ≈ 1.498). The 5th fret plays a perfect 4th (ratio 4:3, close to 2^(5/12) ≈ 1.335).

Cents Deviation

In equal temperament the perfect 5th is slightly narrower than the pure 3:2 ratio, by about 2 cents. That compromise is what lets all keys sound equally in tune, unlike just intonation.

Where The Fret Sits On The Neck

Frequency and distance are two sides of the same number. Pressing at fret n shortens the vibrating string to 1/2^(n/12) of its open length, so the 12th fret leaves exactly half the string and the octave falls out of the geometry rather than out of the tuning.
The result panel prints that ratio for whichever fret you enter. Multiply it by your own scale length to get the sounding length in inches or millimeters, or use the fret spacing calculator for the distance from the nut.