What Are Cents in Music? Tuning Accuracy Explained

Every serious tuner displays "cents" — ours shows values like −12.4 ¢. Understanding this unit turns the tuner from a magic green light into a precision instrument you can actually read.

The definition

A cent is 1/100 of an equal-tempered semitone. Since an octave has 12 semitones, it spans 1200 cents. The scale is logarithmic — matching how our ears perceive pitch — so a cent is the same musical distance whether you're on a bass low E or a violin high E.

When your tuner reads +20 ¢, your note is 20% of the way toward the next semitone up.

How many cents can people hear?

• ±1–2 ¢: essentially perfect; below the just-noticeable difference for nearly all listeners in melodic context.
• ±5 ¢: the classic "good enough" target — most hardware tuners' green zone. Chords sound clean.
• ±10 ¢: trained ears notice, especially in sustained chords, where "beating" becomes audible.
• ±25 ¢: clearly out of tune to most listeners — a quarter-tone off.

Interestingly, two notes played together expose far smaller errors than notes played one after another — the beating between close frequencies is easy to hear. That's why a guitar can sound fine on single-note lines but sour on big open chords.

How accurate does tuning need to be?

Aim for within ±3 cents on every string — the default green zone in our tuner, and tighter than most clip-on tuners. Chasing ±0.5 ¢ on a guitar is futile: pressing a string against a fret bends it several cents sharp anyway, and intonation varies along the neck. Violinists and cellists, who control pitch continuously, can and do land much closer.

Cents vs. hertz — why not just use Hz?

Because the same error in hertz means completely different things across the range. Being 1 Hz off at low E (82 Hz) is about 21 cents — badly out of tune. Being 1 Hz off at high E (330 Hz) is 5 cents — barely noticeable. Cents normalize all of that, which is exactly why tuners use them.