Cents / Pitch Shift Calculator
Convert between cents, semitones and frequency ratios.
Overview
The cents and pitch shift calculator converts between cents, semitones, and frequency ratios so you can quantify any tuning offset precisely. Enter a pitch shift in cents and the tool returns the equivalent semitone count and the frequency ratio; or input two frequencies and it tells you how many cents apart they are.
It's a daily-driver tool for producers using pitch shifters, mastering engineers checking tape speed deviation, intonation specialists setting up guitars, and microtonal composers building non-12-TET scales. Choirs and string ensembles also use cent measurements to discuss small intonation adjustments that aren't large enough to call a semitone.
How it works
A cent is one hundredth of an equal-tempered semitone, so 1,200 cents make up a full octave (12 semitones x 100). Because pitch perception is logarithmic, the conversion uses powers of two: the frequency ratio for n cents is 2^(n/1200). A semitone (100 cents) is 2^(1/12), roughly 1.0595; an octave (1,200 cents) doubles the frequency exactly. Going the other way, cents between two frequencies equals 1,200 multiplied by log base 2 of the ratio.
Cents are useful because the human ear can detect differences of about 5-10 cents on sustained tones, and trained ears notice less. Pure intonation intervals (just thirds, fifths) deviate from equal temperament by small but audible cent amounts: a just major third is 386 cents versus the tempered 400.
Examples
+100 cents → 1 semitone, ratio 1.0595 (A440 → A#466.16)
+700 cents → Perfect fifth, ratio 1.4983 (A440 → E659.26)
A4 = 440 Hz vs A4 = 442 Hz → +7.85 cents (typical orchestra sharp tuning)
Just major third vs equal temperament → -13.7 cents (just is flatter)
FAQ
How small a pitch difference can the human ear detect?
Trained musicians can distinguish 5-10 cents on a sustained tone, and pitch beating between two notes becomes audible at even smaller differences. For percussive sounds, the threshold is higher.
Why are just-intonation intervals different from equal temperament?
Equal temperament evenly divides the octave so all keys sound equally in-tune (and equally slightly out). Just intonation uses small whole-number ratios that sound smoother but only work in one key.
How do I use cents to set guitar intonation?
Tune the open string, fret the 12th fret, and compare. If the fretted note reads sharp (positive cents), move the saddle back. If flat, move it forward. Aim for within +/-3 cents.
What's the cent value of a Pythagorean comma?
About 23.46 cents. It's the gap between twelve perfect fifths and seven octaves, and it's the reason equal temperament was invented.