The short answer
Press Start tuner below and allow the microphone. Play the thickest string open (without pressing a fret). The tuner shows the note and a needle: left of the middle means the string is too low, right means too high. Turn the peg until the needle stays in the green zone, then move to the next string. When all six are done, check them once more, because tuning one string slightly changes the tension on the others.
Standard tuning, from the thickest string (6th) to the thinnest (1st), is E A D G B E. A common memory aid is Eddie Ate Dynamite, Good Bye Eddie.
Try it here: Guitar tuner
Open the full tool pageString notes and frequencies
Each string has a target note and frequency. The values below assume the usual reference A4 = 440 Hz. The number after the letter is the octave: E2 is two octaves below the E above middle C.
| 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 |
Which way to turn the pegs
On most acoustic and electric guitars, turning a peg so that the string winds tighter raises the pitch. The direction depends on which side of the headstock the peg is on, so the safest way is to turn slowly while the string rings and watch the needle. If it moves the wrong way, turn back.
Always tune up to the note rather than down to it. If a string is too high, loosen it a little below the target and then tighten it up to the note: the string then settles against the gear and stays in tune longer. Never tighten far above the target note; a string tuned an octave too high will break.
When the tuner shows the wrong string
A guitar tuner with a guitar preset compares what it hears with the nearest of the six strings. After a string change, a string can be so low that it sounds closer to its neighbour. In that case, press the button of the string you are tuning to lock the tuner to it, raise the pitch until the needle appears near the middle, and press Auto to return.
Background noise, other strings ringing along and hard pick attacks can also confuse the reading for a moment. Mute the strings you are not tuning with your hand, pluck with the thumb and read the needle after the first fraction of a second, because a freshly plucked string starts slightly sharp.
Tuning by ear
Without a tuner you can tune the strings to each other. Tune the low E to a reference, for example the Play reference button of the tuner, a piano or another instrument. Then press the low E string at the 5th fret: that note is A and must sound the same as the open A string. Do the same at the 5th fret of the A string for D and of the D string for G.
The B string is the exception: press the G string at the 4th fret to get B. Then return to the 5th fret, on the B string, for the high E. When two notes are almost but not quite the same, you hear a slow wobble called beating; turn the peg until it disappears.
- 5th fret of the low E = open A
- 5th fret of A = open D
- 5th fret of D = open G
- 4th fret of G = open B
- 5th fret of B = open high E
Alternate tunings
Drop D lowers only the 6th string a whole tone to D, giving D A D G B E. It is used for heavy riffs and for power chords played with one finger. Half step down lowers every string by a semitone (Eb Ab Db Gb Bb Eb), which many rock and blues players use to match a singer or to make bends easier. Open G (D G D G B D) and DADGAD are popular for slide and folk.
The instrument list of the tuner has all of these. For other tunings, choose the chromatic mode and tune each string to the note you need.
Why guitars go out of tune
New strings stretch for several days and keep dropping in pitch. Gently pull each new string away from the fretboard along its length, retune and repeat a few times; this speeds up the process. Temperature and humidity change the length of the strings and the wood, so a guitar taken from a cold car into a warm room needs retuning after it has adjusted.
If a guitar is in tune on the open strings but chords higher up the neck sound off, the problem is the intonation, not the tuning. Compare the harmonic at the 12th fret with the fretted note at the 12th fret: if they differ, the saddle position needs adjusting, which a guitar technician can do.