Tool
The circle of fifths, for guitarists.
Not a poster to memorise — a working map. Click a key to see the six chords that fit, the key signature, and three progressions you can play immediately.
Circle of fifths
Click a key to see its six chords.
Key of C
Six chords that fit
Common progressions
The circle moves in fifths: each step clockwise is a perfect fifth up. Adjacent keys share almost all their chords, which is why key changes feel smooth.
How to read the circle
The twelve keys are arranged by perfect fifths. Moving clockwise takes you up a fifth: C → G → D → A. Moving anticlockwise takes you down a fifth. Neighbouring keys share six of their seven notes, which is why they sound close.
The inner note of each segment is the major key. The six chords in the panel are the diatonic chords of that key: I, ii, iii, IV, V and vi. The seventh chord, vii°, is diminished and is deliberately left out of the beginner view.
Why the guitar loves it
Guitar shapes repeat. A I–V–vi–IV progression in C uses C–G–Am–F; in G it uses G–D–Em–C. The shapes are the same family, just moved. The circle tells you which family you are in and which chords are neighbours.
Three progressions worth knowing
- I–V–vi–IV — the “four chord” progression. In C: C–G–Am–F.
- I–IV–V — the oldest chord loop in popular music. In C: C–F–G.
- ii–V–I — the jazz cadence. In C: Dm–G–C.
How to practise with it
Pick a key. Play the I, IV and V chords in that key. Then play the vi chord and hear how it changes the mood. Finally, use the play buttons to hear the progression before you play it. Do one key per practice session; the relationships will become familiar faster than memorising a diagram.
What is the circle of fifths in one sentence?
It is a map of the twelve keys arranged by perfect fifths, so neighbouring keys share almost all of their notes and chords.
Why does it matter for guitar?
It tells you which chords belong together. In C, the main chords are C, Dm, Em, F, G and Am; the circle shows those relationships at a glance and helps you transpose them to another key.
How do I use it to find the key of a song?
List the chords in the song. Find the key whose six chords cover most of them. The chord the song resolves to — usually the last chord — is often the I chord.
What are the numbers I, ii, iii, IV, V, vi?
They are scale degrees. Uppercase means major, lowercase means minor. The pattern is the same in every key, which is why a I–V–vi–IV progression sounds familiar in any key.
Do I need to memorise the circle?
No. Use it as a reference until the relationships become familiar. The most useful part is knowing that IV and V are next to I, and vi is its relative minor.