How to Tune a Mandolin

A mandolin that’s out of tune sounds terrible no matter how well you play it. The good news: tuning a mandolin is straightforward once you understand the layout and build a routine around it.

This guide covers standard GDAE tuning, every common tuning method (electronic tuners, clip-on tuners, apps, tuning forks, and tuning by ear), plus alternate tunings used in bluegrass, Celtic, and old-time music.

Standard Mandolin Tuning: GDAE

A mandolin has eight strings arranged in four pairs called courses. Each pair is tuned to the same note in unison. From lowest to highest pitch:

Course	Note	Frequency	Position
4th (lowest)	G3	196 Hz	Closest to your chin
3rd	D4	293.66 Hz
2nd	A4	440 Hz
1st (highest)	E5	659.26 Hz	Closest to the floor

This is the same tuning as a violin (GDAE), but each note is doubled. The paired strings create the mandolin’s characteristic shimmering, chorus-like tone.

If you’re coming from guitar, note that mandolin tuning works in fifths (each string is a fifth above the previous one), not fourths like a guitar. This changes how you think about scales and chord shapes.

Identifying Your Tuning Pegs

Look at the headstock at the top of the neck. A standard mandolin has eight tuning pegs — one for each individual string. On most A-style and F-style mandolins, the pegs are arranged in two rows of four, with the G and D course pegs on one side and the A and E course pegs on the other.

Each string in a course has its own peg. When tuning, you adjust one string at a time within each pair, then check them together for unison.

Important: Turn pegs in small increments. Mandolin strings are short and under high tension, so a small turn produces a bigger pitch change than you might expect coming from guitar or banjo.

Method 1: Clip-On Tuner

A clip-on tuner is the most practical option for most players. It detects pitch through vibrations in the headstock rather than sound through a microphone, so it works in noisy environments — rehearsals, jam sessions, backstage.

How to use one:

Clip the tuner onto the headstock.
Set it to chromatic mode (or mandolin mode if available).
Pluck one string of the G course cleanly. Let it ring.
Watch the display. It shows the detected note and whether you’re sharp (too high) or flat (too low).
Turn the tuning peg slowly until the display reads G and the needle centers.
Tune the second G string to match.
Play both G strings together — listen for a smooth, even tone with no warbling or “beating.” A wavering sound means the two strings are slightly off from each other. Keep adjusting until it’s clean.
Repeat for D, A, and E courses.

Recommended clip-on tuners: The Snark SN5X and the Peterson StroboClip are both excellent choices. The Peterson is more precise (0.1 cent accuracy) and worth it if you play frequently. If you also play banjo, check our best banjo tuner roundup — most of those clip-on tuners work just as well for mandolin.

Method 2: Electronic Tuner (Pedal or Desktop)

A pedal tuner like the Boss TU-3 or a desktop tuner works well if you play amplified mandolin. You plug in directly, eliminating background noise entirely.

The process is the same as a clip-on tuner: pluck each string individually, read the display, adjust. Pedal tuners also mute your signal while tuning, which is useful during live performance.

Method 3: Tuner App

Smartphone tuner apps are convenient and often free. GuitarTuna, Pano Tuner, and Cleartune are all solid options.

How to use one:

Open the app and select mandolin or chromatic mode.
Hold your phone near the soundhole (within 15-20 cm works well).
Pluck one string at a time and follow the on-screen indicator.
Adjust the tuning peg until you hit the target note.

The limitation: App-based tuners use your phone’s microphone, so they struggle in noisy rooms. They’re fine for quiet practice at home but unreliable at a jam session. For violin tuning with similar paired-string considerations, see our best violin tuner guide.

Method 4: Tuning Fork

A tuning fork is old-school and reliable. Most tuning forks produce A4 at 440 Hz — the same as your mandolin’s open A strings.

Strike the fork against your knee or a hard surface (not the mandolin itself — you can dent the finish).
Touch the base of the vibrating fork to the mandolin’s body or bridge. You’ll hear a clear A note.
Pluck your open A string and compare. Adjust until the two pitches match — when they’re close, you’ll hear a slow “beating” that disappears as you get in tune.
Once A is tuned, use relative tuning (see below) to tune the remaining strings from there.

This method trains your ear better than any electronic device. It’s slow at first but becomes second nature with practice.

Method 5: Tuning the Mandolin to Itself

If you have one string you trust is in tune — or you just need your mandolin to sound good on its own without matching concert pitch — you can tune the remaining strings relative to that one.

The method uses the fact that mandolin strings are tuned in fifths:

Start with G (4th course). Assume it’s correct, or tune it with a reference pitch.
Tune D from G: Press the G string at the 7th fret. This produces a D. Pluck the open D string and adjust until they match.
Tune A from D: Press the D string at the 7th fret. This produces an A. Match the open A string to it.
Tune E from A: Press the A string at the 7th fret. This produces an E. Match the open E string to it.

You can also use the 5th fret method: pressing the G string at the 5th fret gives you a C, not a D — so on mandolin (tuned in fifths), the 7th fret is correct. This is a common point of confusion for guitarists, where the 5th fret method works because guitars are tuned in fourths.

Cross-check: After tuning all strings, play some open chords (G major, D major) and listen for anything that sounds off. Go back and fine-tune as needed.

Tuning to Another Instrument

When tuning your mandolin to match a guitar, piano, or another mandolin:

Make sure the reference instrument is itself in tune.
Match your A string to the reference instrument’s A first — A440 is the universal standard.
Tune the remaining strings from there using your tuner or the relative method above.
Play a few chords together with the other instrument to check.

If you’re playing with a guitarist, have them play their open G, D, A, and E notes while you match each course. Since mandolin and guitar share these note names (though in different octaves), this works naturally.

Tips for Staying in Tune

Mandolins go out of tune more often than guitars. The shorter scale length and higher string tension make them more sensitive to temperature, humidity, and playing intensity. Here’s how to minimize drift:

Always tune up to the note, never down. If you overshoot, drop below the target and come back up. Tuning up locks the string against the nut; tuning down can leave slack that slips later.
Stretch new strings. After restringing, gently pull each string away from the fretboard a few times, retune, and repeat. New strings need 2-3 days of stretching before they stabilize.
Check your tuning pegs. If a peg slips or won’t hold, it may need tightening (on friction pegs) or replacement. Geared tuners are more stable than friction pegs.
Store your mandolin properly. Avoid leaving it in a hot car, near a heater, or in very dry or humid conditions. A hardshell case with a humidifier helps in extreme climates.
Retune between songs. At gigs and jams, a quick check between songs prevents gradual drift from becoming noticeable. The best mandolin players do this constantly — it’s not a sign of a bad instrument.

Alternate Tunings

Standard GDAE covers most playing situations, but alternate tunings open up different chord voicings, drone effects, and genre-specific sounds. Here are the most useful ones:

GDGD — Sawmill Tuning (Cross G)

Drop the A strings down to G and the E strings down to D. This gives you two pairs of octave G and D strings, creating a droning, open sound perfect for old-time Appalachian fiddle tunes. The doubled open strings let you play melody on one course while the other drones underneath.

GDGB — Open G Tuning

Retune the A strings down to G and the E strings down to B. Strumming all open strings produces a G major chord. This tuning is popular in blues and folk music and works well with a slide.

GDAD — Gee-Dad Tuning

Drop only the E strings down to D. This creates an open, suspended sound widely used in Irish and Celtic music. It’s a favorite among Irish mandolin and bouzouki players because it makes Celtic modal accompaniment patterns easy to finger.

FCGD — Cajun Tuning

Tune every string down one whole step from standard. This lowers the overall pitch and tension, producing a warmer, darker tone suited to Cajun and Creole music. Same fingerings as standard tuning, just a step lower.

ADAE — High Bass / Old-Timey D Tuning

Raise the G strings up to A. This narrows the range and puts emphasis on the key of D, which suits old-time and traditional American fiddle tunes.

AEAE — Cross A Tuning

Raise the G to A and the D to E. This creates an open A5 sound (no third, so it’s neither major nor minor) and works well for modal old-time tunes in the key of A.

A note on string tension: Some alternate tunings raise pitch significantly (like AEAE), which increases tension and can stress strings or the instrument’s neck. If you regularly use a tuning that raises pitch, consider using lighter gauge strings. Conversely, tunings that lower pitch (like FCGD) reduce tension and may cause buzzing — heavier strings can help. If you’re shopping for a mandolin or a quality mandolin under $1,000, look for one with a solid, well-braced top that handles alternate tunings without issues.

Quick Reference

Standard tuning: G3-D4-A4-E5 (low to high), same as a violin.

Fastest tuning method: Clip-on tuner in chromatic mode.

Best ear training method: Tuning fork (A440) plus relative tuning from the A string.

How often to tune: Every time you pick up the instrument, and between songs during performance.

Going out of tune constantly? Check your tuning pegs, nut slots, and bridge. New strings need 2-3 days to settle.