How-To Guides·6 min read·

How to Tune a Ukulele: High G and Re-entrant Setup

Learn how to tune a ukulele properly: explaining why the re-entrant high G confuses beginners, tuning pegs, string stretch, and octave checks.

By Audio Tests Online Editorial Team

The ukulele is one of the most accessible stringed instruments in the world. Almost every beginner still meets the same puzzle in their first tuning session: why does the 4th string sound higher than the string next to it?

Understanding the ukulele’s re-entrant tuning prevents snapped strings, wrong-octave mistakes, and a lot of confusion about what the tuner is telling you.

1. The Mystery of the Re-entrant G String

On guitars, violins, cellos, and banjos, string pitch ascends in order from low to high across the neck. Beginners pick up a soprano, concert, or tenor ukulele and assume the 4th string, the one closest to the chin, is the lowest pitch on the instrument.

It is not.

Standard ukulele tuning is re-entrant (g4–C4–E4–A4):

  • String 4: High G (G4 = 392.00 Hz)
  • String 3: Middle C (C4 = 261.63 Hz), the lowest pitch on the instrument
  • String 2: E (E4 = 329.63 Hz)
  • String 1: A (A4 = 440.00 Hz), the highest pitch

In pitch order the strings run C4, E4, G4, A4. In physical order they run G4, C4, E4, A4, so the 4th string is the second-highest note on the instrument, not the lowest. The re-entrant set covers only a major sixth (C4 to A4, 9 semitones), while a guitar’s open strings span two octaves. That close voicing, not the body size alone, is a large part of the ukulele’s sound.

Two alternatives change the layout. Low G replaces the high G4 string with G3 = 196.00 Hz, one octave lower, so the strings run G3–C4–E4–A4 like a small guitar. Baritone ukuleles are larger and tuned D3–G3–B3–E4, the same notes as the top four guitar strings. The tuner cards follow physical string order, so the top card is the high G; if a reading looks like the wrong octave, check which card is highlighted.

2. Step-by-Step Tuning Procedure

Step 1: Tune string 3 (C4) first

String 3 is the lowest pitch on a standard ukulele (C4 = 261.63 Hz), so it makes an acoustic foundation. Pluck open string 3 and watch the needle on the Ukulele Tuner: a needle left of centre means flat, so tighten the peg; a needle right of centre means sharp, so loosen past the note and tune back up.

Step 2: Tune string 2 (E4)

Tune string 2 to E4 = 329.63 Hz, a major third above the C string.

Step 3: Tune string 1 (A4)

Tune string 1 to A4 = 440.00 Hz, which matches international concert pitch. The tuner’s default tolerance is ±3 cents; at 440 Hz that is about 0.76 Hz.

Step 4: Tune string 4 (High G4) last

This is where mistakes happen: do not tune string 4 an octave too low, and do not tune it so high that it snaps.

  • Target: G4 = 392.00 Hz, not G3 = 196.00 Hz.
  • Ear check: fret string 2 (E) at the 3rd fret. That fretted note is G4, and open string 4 should match it in unison.

Pluck cleanly

Use the side of your thumb or a soft finger pad over the 12th fret, and rest your plucking hand across the other three strings. A ringing neighbour can take over the display because the strings overlap in pitch.

3. Dealing with Nylon String Stretch

New nylon, nylgut, or fluorocarbon strings stretch. If you have just installed fresh strings or bought a new ukulele, they may drop out of tune within thirty seconds of playing. That is polymer creep under tension, not broken tuning pegs.

How to settle new strings

  1. Tune all four strings to pitch.
  2. Place your fingers under each string near the soundhole and pull gently 1 to 2 cm away from the fretboard.
  3. Retune each string back to pitch.
  4. Repeat the stretch-and-retune cycle three or four times across all strings.
  5. Within 2 to 3 days of regular playing, the strings stabilise and hold pitch.

If a fresh string drops a semitone within a minute, check the knot at the bridge before blaming the peg; a slipping knot looks exactly like a slipping tuner. Do not pre-stretch by tuning above pitch: the 1st string is the thinnest in the set, and an A5 attempt is roughly double the tension the instrument is built for.

4. Friction Pegs vs. Geared Tuners

The two peg types behave differently:

  • Geared tuners: pegs stick out from the sides of the headstock with visible cog gears, usually at a 14:1 or 16:1 ratio. Fourteen turns of the button turn the string post once, so small button movements make small pitch changes, and the worm gear holds the setting.
  • Friction pegs: pegs point straight back through the headstock, common on traditional soprano models. They rely on compression screw tension and need light inward pressure while you turn. If a peg slips backward when you release it, tighten the screw on the back of the button a little at a time; if it binds, back the screw off.

A wound low-G string is thicker than the high G it replaces, so check that it slides freely in the nut slot before bringing it to pitch.

Accuracy, limits and troubleshooting

  • The ukulele is quiet, so distance hurts. Hold the instrument close to the microphone and tune in a quiet room. The strings are well inside a small microphone’s range; it is the small body’s output that makes the reading fragile.
  • A ringing neighbour is the most common bad reading. Rest your hand across the other three strings while you pluck one.
  • Octave errors are easy to make and hard to hear. Read the note name on the card, not just the needle position.
  • Support the neck while you tune. A ukulele neck is light, and pulling hard on a peg with the body unsupported strains the joint.
Symptom Likely cause Fix
Reading sits a whole octave off Wrong octave for the string Read the card, tune from below
Pitch drops within a minute of tuning New strings creeping, or a slipping bridge knot Stretch and retune, check the knot
Friction peg slips when released Screw tension too light Tighten the screw a little at a time
Reading jumps between notes Neighbouring strings ringing Mute the other three strings

Academic & Scientific References