Twelve strings, ten pitches
A 12-string is a normal guitar where every string has a twin, arranged in six courses that you fret and strum as one. The twins are not all the same, which is the entire reason this instrument needs its own note map:
- The four lower courses — E, A, D and G — pair the normal string with a much thinner one tuned a full octave higher. That octave shimmer is the 12-string sound.
- The two top courses — B and E — are unison pairs. Both strings take exactly the same pitch.
So twelve strings produce only ten distinct pitches. Tune one string of a course at a time, and read the octave number as well as the letter — that is what tells you whether you are on the D3 main string or the D4 octave string.
- E26th course · main string82.41 Hz
- E36th course · octave string164.81 Hz
- A25th course · main string110.00 Hz
- A35th course · octave string220.00 Hz
- D34th course · main string146.83 Hz
- D44th course · octave string293.66 Hz
- G33rd course · main string196.00 Hz
- G43rd course · octave string — the fragile one392.00 Hz
- B32nd course · unison pair, both strings246.94 Hz
- E41st course · unison pair, both strings329.63 Hz
Tap a tone to hear the target, or play each string into the tuner above and centre the needle. Mute the partner string with a fingertip while you tune its twin.
The tuning routine
- Work course by course, thickest to thinnest. Within each course, tune the main (thicker) string first, then its octave or unison partner.
- Mute the partner while you tune. Two strings sounding at once — especially a unison pair — make the dial hunt between them. Rest a fingertip on the one you are not tuning and the reading locks instantly.
- Go gently on the 3rd course octave string (G4). It is the thinnest string on the instrument and sits at the highest tension relative to its gauge. This is the string that snaps, and it snaps while being tuned up. Approach it slowly and stop the moment the needle centres.
- Do a second pass — this one is not optional. A 12-string carries close to double the tension of a 6-string, so the neck flexes measurably as you work. The courses you tuned first will have drifted by the time you finish the last.
- Strum and listen for warble. Unison pairs that are a few cents apart beat audibly. Octave pairs are more forgiving, but a badly-out octave string sounds sour rather than shimmering.
Why 12-strings drift more than 6-strings
Nothing is wrong with your guitar. Twice the strings means roughly twice the pull on the neck and top, and that load shifts every time you make a significant change. Add the fact that twelve strings each have their own winding, their own stretch and their own friction at the nut, and small movements accumulate faster than on a 6-string. New strings on a 12-string can need three or four passes before they settle. Our tuning stability guide covers what to do about the nut and the string windings, both of which matter more here.
Frequently asked questions
Is there a 12-string tuner app I don't have to install?
This page is one — it runs in your browser through the microphone, with no install, no account and no ads, and the audio is analysed on your device rather than uploaded. It works the same on a phone propped against the guitar, a tablet or a laptop, and the reference tones above work even with no microphone at all.
What are the notes on a 12-string guitar?
From the thickest course to the thinnest: E2+E3, A2+A3, D3+D4, G3+G4, B3+B3, E4+E4. The lower four courses are octave pairs, the top two are unisons — ten distinct pitches across twelve strings. Tap any tone above to hear its target.
Which string keeps breaking on my 12-string?
Almost certainly the 3rd course octave string, G4. It is the thinnest string on the guitar and it is tuned to a higher pitch than any other single string, leaving it very little headroom. Break it repeatedly and you have three good options: tune the whole guitar to E♭, fit a lighter gauge for that one string, or check the nut slot and bridge for a sharp edge that is cutting it.
Can I tune a 12-string with a normal guitar tuner?
Yes, provided it is chromatic rather than a six-note guitar-only tuner. A chromatic tuner names any note it hears, which is exactly what you need for the octave strings — a guitar tuner that only recognises E, A, D, G, B and E will report the G4 octave string as a “G” without telling you it is an octave off. The full walkthrough is in our 12-string tuning guide, and the 6-string tuner covers standard guitars.