How to tune a guitar: standard tuning notes and using a tuner

Standard guitar tuning, from the lowest string to the highest, is E A D G B E. Each string has a target frequency, based on A4 = 440 Hz, and a tuner shows how far off a string is in cents. Tune each string to its note, and approach each note from below, so the string does not slip. The table below lists the target frequency for each string.

Guitar tunerStrings sound out of tuneDo it free

The target notes and frequencies

String	Note	Frequency (Hz)
6th (thickest)	E2	82.41
5th	A2	110.00
4th	D3	146.83
3rd	G3	196.00
2nd	B3	246.94
1st (thinnest)	E4	329.63

These numbers follow from equal temperament, the system most modern instruments use. Each semitone multiplies the frequency by the twelfth root of 2, which is about 1.0595. A note n semitones above A4 has the frequency 440 × 2^(n/12). E4 is 5 semitones below A4, so it is 440 × 2^(−5/12) = 329.63 Hz. The ISO standard ISO 16:1975, "Acoustics: Standard tuning frequency," sets A4 at 440 Hz, which is why tuners use it as the default reference.

Reading the tuner in cents

A cent is one hundredth of a semitone. A tuner measures the frequency of the string and shows the difference in cents from the target. The formula is:

cents = 1200 × log₂(measured ÷ target)

For example, a high E that measures 331 Hz against a target of 329.63 Hz is 1200 × log₂(331 ÷ 329.63) = about 7 cents sharp. Many players aim to be within a few cents of the target, and a tuner needle centred in the middle is the usual goal.

Tune step by step

1. Set the tuner's reference to A4 = 440 Hz, unless you have a reason to use another pitch.
2. Pluck the 6th string and read the note. Tune it up or down to E2.
3. If the string is flat, tune it up past E2, then bring it down to the note. Approaching from below keeps the string from slipping at the tuning post.
4. Repeat for each string, one at a time.
5. Check again after a few minutes, since new strings settle.

Without a tuner, you can check the strings against each other. Fret the low E string at the 5th fret to get an A, which should match the open A string. Repeat that pattern for the other strings: the 5th fret of A gives D, the 5th fret of D gives G, the 4th fret of G gives B, and the 5th fret of B gives E.

Drop D, bass and ukulele

Drop D lowers only the 6th string by two semitones, from E2 to D2, which is 73.42 Hz. Keep the other five strings in standard tuning. Drop D is popular in rock and metal for heavy power chords.

A four-string bass in standard tuning uses the frequencies E1 41.20 Hz, A1 55.00 Hz, D2 73.42 Hz and G2 98.00 Hz. A ukulele in its common GCEA tuning uses G4 392.00 Hz, C4 261.63 Hz, E4 329.63 Hz and A4 440.00 Hz. On a ukulele the G string is "re-entrant": it is tuned high, above the C.

The guitar tuner has presets for these tunings, and it can also tune violin and chromatic instruments.

Why strings go out of tune

• New strings stretch and settle over the first few days.
• Temperature and humidity change the wood and the tension, so a guitar moved between rooms often needs a retune.
• Strings can slip at the tuning post when they are wound badly or pulled too sharply.
• Bending strings, heavy playing and a loose capo all shift the tension.

If the tuner does not respond at all, the problem may be the microphone rather than the guitar. See microphone not working and run the microphone test.

Train your ear and your timing

A tuner is faster than your ear at first, but an ear that can hear a difference is useful too. Play a reference note with the tone generator, set to the target frequency, and match the string to it. Use a steady beat when you practise scales or chord changes. The metronome lets you start slow, say 60 beats per minute, and raise the tempo only when the pattern is clean.

Quick answers

Should I tune to 440 Hz or 432 Hz? Use 440 Hz for standard guitar tuning. Other pitches exist, but they are not the standard for guitars.

Which string should I tune first? Most people start with the 5th string (A) or the 6th (E), then tune the others from them.

Can I tune with a phone app? Yes, if the room is quiet and the app can hear the string clearly through the microphone.

Do I need to retune after every session? Not always, but check the tuning before each session. Strings slip more after big changes in temperature or after a new set.