Free · No download · Any device
Acoustic Guitar Tuner
The tuner listens through your microphone.
Tune your acoustic guitar with your phone or computer’s microphone. Play a string and the tuner shows the note and how far off it is, for steel-string and classical (nylon-string) guitars alike.
- Hears an acoustic guitar clearly through the built-in microphone
- Standard tuning, Drop D, DADGAD, open tunings and chromatic mode
- Works on phones, tablets and computers
Standard tuning: E A D G B E
From the thickest string to the thinnest, these are the notes and frequencies the tuner aims for in standard tuning:
| String | Note | Frequency |
|---|---|---|
| 6th (thickest) | E2 | 82.41 Hz |
| 5th | A2 | 110.00 Hz |
| 4th | D3 | 146.83 Hz |
| 3rd | G3 | 196.00 Hz |
| 2nd | B3 | 246.94 Hz |
| 1st (thinnest) | E4 | 329.63 Hz |
How to tune an acoustic guitar
- Press Start tuning and allow microphone access.
- Hold or place your device about 30 cm (a foot) from the soundhole, in a fairly quiet room.
- Pluck the 6th (thickest) string and let it ring. Needle left means flat — tighten the string; needle right means sharp — loosen it.
- When the display turns green, move on to the next string. After all six, check them once more.
New to tuning? The step-by-step guide explains which way to turn the pegs and how to tune by ear.
Why acoustic guitars go out of tune
An acoustic guitar is mostly thin wood, and wood swells and shrinks with humidity and temperature. Taking the guitar from a cold car into a warm room, or through a change of season, is enough to pull every string off pitch — so tune each time you pick it up, after it has had a few minutes to reach room temperature.
New strings stretch for the first few days and need frequent retuning. Gently pulling each new string away from the fretboard along its length, then retuning, helps them settle faster.
Classical and nylon-string guitars
Classical guitars use the same standard tuning, E A D G B E, so the tuner works exactly the same way. Nylon strings stretch much more than steel, so a freshly strung classical guitar can take several days of retuning before it holds its pitch.
Popular acoustic tunings
-
D A D G B E
Drop D
Standard tuning with the low E lowered a whole step to D — heavier riffs and one-finger power chords.
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D A D G A D
DADGAD
An open, ringing modal tuning from Celtic and folk music that also made its way into rock.
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D G D G B D
Open G
Strum the open strings and you hear a G major chord — the classic sound of slide guitar and Stones riffs.
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D A D F♯ A D
Open D
The open strings form a D major chord — full, resonant and ideal for slide and fingerstyle folk.
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E♭ A♭ D♭ G♭ B♭ E♭
Half Step Down (E♭)
Every string lowered one semitone — slinkier strings and a darker tone, loved by blues and rock players.
-
C G C G C E
Open C
A low, rich C major chord on the open strings — a deep, piano-like tuning for fingerstyle and ambient playing.
Frequently asked questions
Can I tune an acoustic guitar with my phone?
Yes. Open this page in your phone’s browser, press Start tuning and allow microphone access. The phone’s microphone hears an acoustic guitar easily — no app or clip-on tuner needed.
Is acoustic guitar tuning different from electric?
No. Both use standard tuning, E A D G B E, from the thickest string to the thinnest, and the same alternate tunings. See the electric guitar tuner for tips specific to electric guitars.
Does it work for a 12-string guitar?
Yes, in Chromatic mode. Tune each pair one string at a time, muting the other string of the pair: the lower four pairs have one string an octave higher, and the top two pairs are tuned in unison.
How often should I tune my acoustic guitar?
Every time you play. It only takes a minute, and changes in temperature and humidity mean an acoustic guitar rarely holds its tuning perfectly from one day to the next.