Standard tuning, string by string
The convention that almost every modern guitar method assumes is EADGBE — from the lowest (thickest) string to the highest (thinnest). Written with octave numbers, those notes are E2, A2, D3, G3, B3, and E4. The target frequencies, when A4 is set to 440 Hz in equal temperament, are approximately:
- 6th string — E2, ≈ 82.41 Hz
- 5th string — A2, ≈ 110.00 Hz
- 4th string — D3, ≈ 146.83 Hz
- 3rd string — G3, ≈ 196.00 Hz
- 2nd string — B3, ≈ 246.94 Hz
- 1st string — E4, ≈ 329.63 Hz
The intervals between adjacent strings are four semitones (a perfect fourth) everywhere except between the G and B strings, where the interval is three semitones (a major third). That one irregular gap is what makes many chord shapes playable on a guitar; it also explains why open chords tend to "lay under the hand" in certain keys and feel awkward in others.
Reference pitch: A440 and its siblings
Most chromatic tuners default to A4 = 440 Hz. Some classical ensembles tune slightly higher (A4 = 441 or 442 Hz) to project a brighter sound, and some historical-performance groups use lower baroque pitches such as A4 = 415 Hz. For a solo guitar at home, A = 440 Hz is the safest choice because every recording, backing track, and piano you are likely to play along with assumes it.
What "cents" are, in plain English
A cent is one hundredth of a semitone. Because the ratio between adjacent semitones is fixed, a cent is a small, consistent unit regardless of which octave you are in. A few benchmarks:
- Within ±5 cents of the target: considered "in tune" for practical purposes, and what a chromatic tuner typically displays as a green indicator.
- About 10 cents: an attentive ear can usually hear the difference on a sustained note.
- About 25 cents: roughly a quarter-tone — clearly out of tune in a harmonic context.
- 100 cents: a full semitone — a different note.
How to tune with a chromatic tuner
- Play one string at a time, cleanly, and let it ring. Mute the other strings with your picking hand so the tuner sees a single pitch.
- Read the note name the tuner identifies. If it's a semitone or two off, tune toward the correct name first, then worry about fine-tuning.
- Watch the cents indicator. Flat = tighten the string. Sharp = loosen.
- Prefer tuning up to pitch. If you are currently sharp, slacken below the target first, then tighten back up. This reduces the influence of backlash in the tuning machine and slack in the string.
- Go through all six strings, then return to the first one and check again. Tuning one string changes tension on the neck slightly, which can nudge the others.
Common alternate tunings
Drop D (DADGBE)
The low E string is dropped a whole step to D2 (≈ 73.42 Hz). This puts a power-chord shape under a single finger on the bottom three strings and gives the low end a heavier, darker weight. Extremely common in rock, metal, folk, and fingerstyle arrangements.
Half-step down (Eb Ab Db Gb Bb Eb)
Every string is tuned down one semitone. Used by many blues and rock players, sometimes for vocal-register reasons, sometimes to give the strings a slightly looser feel for bending.
DADGAD
A modal tuning beloved in Celtic and fingerstyle traditions. Strumming all six open strings produces a sustained Dsus4 chord, which invites drone-based playing and moveable shapes up the neck. Excellent for harmonics-heavy arrangements.
Open G (DGDGBD)
Strumming the open strings sounds a G major chord. A classic slide-guitar tuning and a Rolling Stones staple. Also produces surprisingly easy one-finger chord voicings up and down the neck.
What "intonation" means — and why octaves matter
A guitar can be in tune at the open strings but sound out of tune higher up the neck. That is an intonation problem, not a tuning problem. The fix is usually at the bridge: the saddles are adjusted so that the fretted note at the 12th fret is exactly one octave above the open string — that is, exactly 1200 cents higher. If the 12th-fret note is sharp relative to the open string, the saddle is moved back (away from the neck); if it is flat, the saddle is moved forward. This is often a one-time setup per string-gauge change rather than something you adjust in daily practice.
Why strings go out of tune
- New strings stretch. A fresh set will go flat several times in the first day. Tune, play for a few minutes, tune again.
- Temperature and humidity shift. A guitar carried from a warm car into a cold venue — or the other way around — will drift. Re-tune after the instrument has acclimated.
- Hard playing and bends pull strings out of their resting position in the nut slots. A pencil graphite rub in the nut slots helps the string return.
- Worn strings. Old strings intonate unevenly, sound dull, and drift faster. If you retune every few minutes even when nothing else has changed, replace the strings.
- Loose tuning machines. If a machine head wobbles or the post slips, the string cannot hold any pitch reliably. Tighten the hardware or have a tech look at it.
Practical tuning tips
- Tune in as quiet a space as you can. Background noise and nearby speakers confuse microphone tuners.
- If possible, play into the microphone rather than holding the guitar at arm's length.
- Check tuning after you have warmed up, not just the moment you pick up the guitar. A cold instrument and a cold player both settle over the first few minutes.
- If a chord sounds off but the tuner says everything is fine, try fretting with slightly less pressure. Pressing too hard sharpens notes.
- For recording, check tuning between takes. Drift that is imperceptible when you play is very audible on a multi-track mix.
Put it into practice
Try the Harmonoise Guitar Tuner to run through the standard tuning above, then experiment with Drop D or a half-step down and hear how the same chord shapes change character. Once your tuning feels solid, the Metronome is a good companion for building rhythmic accuracy on top of pitch accuracy.