Circle of Fifths for Guitar: Keys, Chords and Progressions Made Simple

The circle of fifths arranges the 12 major keys so that each one is a perfect fifth (seven semitones) above the one before it: C G D A E B F# Db Ab Eb Bb F, then back to C. For guitarists it answers one practical question fast: which chords belong together. The key you're in and its two neighbours on the circle are your I, IV and V chords; their relative minors are ii, iii and vi.

The circle as a table

Going clockwise adds one sharp to the key signature; going counter-clockwise adds one flat.

A relative minor uses the same notes as its major key, starting from a different home note. On guitar it's three frets below the major root: A minor is three frets below C.

Find the chords in any key

Pick a key on the circle. Then:

1. The key itself is the I chord.
2. The neighbour clockwise is V.
3. The neighbour counter-clockwise is IV.
4. The relative minors of those three are vi, iii and ii.

In the key of G: I = G, V = D, IV = C, vi = Em, iii = Bm, ii = Am. Those six chords cover most pop, rock and folk songs in G. (The seventh chord, the diminished vii, F#dim, is used much less often.)

Progressions you can build from it

• I–IV–V–I (G C D G): the backbone of rock and roll, country and blues.
• I–V–vi–IV (G D Em C): the most common pop progression of the last decades.
• ii–V–I (Am D G): the core of jazz harmony. Notice that each chord moves one step counter-clockwise around the circle; that pull towards the next fifth is what makes it resolve.
• 12-bar blues: four bars of I, two of IV, two of I, then V, IV, I and V.

Why it matters on guitar

• Choosing a key for open chords. Keys near the top of the circle (C, G, D, A, E) use the most open strings. Further around, use a capo: our capo chart shows which shapes give Bb or Eb without barre chords.
• Transposing. Moving a song from G to A means moving the whole I–IV–V group two steps clockwise around the circle: G C D becomes A D E.
• Changing key in a song. Neighbouring keys share six of seven notes, so modulating one step around the circle sounds smooth; jumping across it sounds dramatic.
• Improvising. Over a progression in G, the G major scale (or E minor pentatonic) fits every chord. Our guide to the pentatonic scale shows the shapes.

Practise it with chords and scales

Struno has a chord library with ready-made progressions, including I–IV–V–I, ii–V–I and the 12-bar blues: pick a key and practise the changes straight away. Its 12 scales and modes are drawn on the fretboard in any key, so you can see how the scale for a key lines up with its chords.

FAQ

What is the circle of fifths used for?

It shows how keys relate: their key signatures, which chords belong to each key, relative minors and which keys are close enough for smooth key changes.

How do I memorise the circle of fifths?

Learn the order of sharps with a phrase like "Father Charles Goes Down And Ends Battle" (F C G D A E B). Each new sharp's key is a fifth above the last. The flats are the same phrase backwards: B E A D G C F.

Is it the same as the circle of fourths?

Yes, read in the opposite direction. Counter-clockwise, each key is a fourth above the previous one, which is the direction ii–V–I moves.