How to tune the guitar

Before we get into how to tune a guitar, there are a few things that need to be discussed so the guitar stays in tune longer.
The first has to do with how you string the guitar.

When you put new strings on a guitar, here are the steps that need to be taken to ensure an effective tuning.
1.) Only do a maximum of 3 windings around the tuning post.
This means less slippage and less windings that need to settle tightly around the post.

2.) Stretch the strings once they are on the guitar. This is done by pressing the string at the 12th fret and pulling gently between the 12th fret and the bridge. You may need to do this a few times as you retune the string back up to pitch.
Some tips when tuning a guitar.
1.) Always tune up to the note, not down. What happens when you tune down is that the string windings loosen around the post, so pretty soon the string will go even slacker and out of tune again.
If the string needs to be tuned lower, it's better to go down below the desired pitch first, and tune it back up from there.

2.) Old guitar strings have a tendency to be difficult to tune, mostly because the metal is fatigued and won't vibrate accurately at the correct fret intervals, so best to change the strings when they get too old.

3.) Make sure that the intonation on the guitar is correct. Intonation is determined by how far the bridge is from the nut.
If the bridge is set too far back, the string will play flatter as you go up the neck, and if it's set too far forward, all the notes will become sharper as you go up the neck.
Intonation is set by checking that the note played at the 12th fret is exactly an octave above the open string note.
You can check this with a guitar tuner and set the bridge accordingly.


How to tune the guitar with a tuner

Most guitar tuners will give you the note names of the strings, making it quite easy to tune the guitar, but some tuners, like those found on guitar processors, are chromatic tuners - meaning they read the signal from the guitar and display the nearest note to it, and tell you by how much it's sharp or flat.

If the guitar string is sharp, the needle, or display lights will move to the right, which means you have to loosen the string a bit, and if the guitar string is flat, the indicator will be to the left, and you'll have to tighten the string a bit.

Chromatic tuners allow you can tune the guitar to any tuning you like.
With that in mind, maybe it's best to know the note names of the individual strings so you can tune them correctly.

Here is the standard guitar tuning.
1st string - E (Thinnest string)
2nd string - B
3rd string - G
4th string - D
5th string - A
6th string - E (Thickest string)

Here's a free guitar tuner I made using a midi file converted to mp3. It goes from the lowest E string to the highest.
Right click on the link and choose "save target as" - Free guitar tuner

Here's something else to keep in mind when tuning the guitar.

Guitar strings play slightly higher in pitch when first struck, so wait a second or two before adjusting the string tension.
The lighter the gauge of string, the more pronounced this effect will be.

Some people prefer to tune their guitars slightly flat on the thicker strings. I personally don't do this because my picking technique tends to lessen the initial impact.

How to tune the guitar to itself

If you don't have a guitar tuner available, you can always tune the guitar to itself.
An easy way to do this is with the following method.

First find a reference for the low E (6th string) - You can use this Low E reference note, another instrument, or get a good estimate off any music that you know the chords to.
Now that you've got a good reference note, tune your 6th string to E

Play the 5th fret on the 6th string and tune the 5th string till the frequencies match. You should hear a rhythmic oscillation that gets slower and slower as the 5th string gets closer to the pitch of the 6th strings 5th fret. When they sound like one note being played, then the 5th string and 6th string are in tune.

Now we do the same for the 5th and 4th string, as well as the 4th and 3rd string, each time playing the note at the 5th fret and tuning the next string till the frequencies match.

At the 3rd string, we play the note at the 4th fret (Not the 5th) and tune the 2nd string to match.
On the 2nd string we again play the 5th fret and tune the first string to that note.
How to tune the guitar to itself
Here's a picture to illustrate the process, all nice and colorful.
The same colored dots should be at the same pitch, or frequency.
The Electric Guitar

How to tune the Guitar

How to use a Plectrum

Beginner Guitar Chords

How to play Barre Chords

How to play Power Chords

Guitar Scales

The C major scale on Guitar

The Pentatonic Scale on Guitar