What is a cent?
Western equal temperament divides an octave into twelve semitones and each semitone into 100 cents. That makes an octave 1,200 cents. A tuner uses cents to show the distance between the pitch it hears and the nearest target note; a negative number is flat and a positive number is sharp.
How close is close enough?
For careful recording, aim for roughly ±2 cents once the note settles. For normal practice or live rhythm playing, ±5 cents is generally a practical target. Guitar attack, fretting pressure, string age, and intonation make perfectly fixed zero-cent readings unrealistic.
Why the reading moves
A plucked string often begins slightly sharp because the pick stretches it, then settles flatter as the vibration decays. Judge the stable portion of the note rather than chasing every instant of movement.
Step-by-step check
- Tune the open string until the tuner identifies the correct note.
- Wait for the attack to settle.
- If the display is negative, tighten the string slightly.
- If it is positive, lower below the note and approach again.
- Stop when the stable reading remains near zero.
Reliable tuning habits
Work with one string at a time, use a moderate and repeatable picking attack, and let the initial pitch settle briefly. Make the final adjustment by approaching the target from below so slack is taken out of the tuning post and nut. After all six strings are close, repeat the entire pass because every tension change can slightly affect the other strings.