What Is the Circle of Fifths?
The Circle of Fifths is one of music theory's most useful reference diagrams. It arranges all 12 major keys — and their relative minor keys — around a circle, positioned so that each key is a perfect fifth away from its neighbors. Tunerium's interactive version lets you click any key to instantly see its notes, key signature, chords and the keys most closely related to it.
Why "Fifths"?
Starting at C and moving clockwise, each step lands on the note a perfect fifth above the last: C to G, G to D, D to A, and so on. After 12 steps, the pattern returns exactly to C, closing the circle. Moving counterclockwise instead moves in perfect fourths, which is why the same diagram is sometimes called the Circle of Fourths depending on which direction you're reading it.
How to Use This Circle of Fifths Tool
- Click any wedge on the wheel — the outer ring shows major keys, the inner ring shows each one's relative minor.
- Read the selected key's scale notes and key signature in the panel below.
- Check the diatonic chords row to see every chord that naturally belongs to that key, labeled with roman numerals.
- Use the closely related keys buttons to jump to the dominant, subdominant, or relative minor/major — the keys a piece is most likely to modulate to.
Reading Key Signatures From the Wheel
Moving clockwise from C, each key picks up one additional sharp: G has 1 sharp, D has 2, A has 3, and so on up to C♯ major with 7 sharps. Moving counterclockwise, each key picks up one additional flat: F has 1 flat, B♭ has 2, E♭ has 3, down to C♭ major with 7 flats. The keys at the bottom of the circle — F♯ and G♭ — are enharmonically identical, sitting at the point where the sharp and flat sides of the circle meet.
| Direction | Each step adds | Example progression |
|---|---|---|
| Clockwise | +1 sharp | C → G (1♯) → D (2♯) → A (3♯)… |
| Counterclockwise | +1 flat | C → F (1♭) → B♭ (2♭) → E♭ (3♭)… |
Finding Closely Related Keys
The keys immediately next to any given key on the wheel are its most closely related keys, sharing all but one note:
- Dominant — one step clockwise, built on the 5th scale degree. Strongly pulls back toward the original key.
- Subdominant — one step counterclockwise, built on the 4th scale degree. Common destination for a IV chord or a modulation.
- Relative minor/major — same wedge, opposite ring. Shares an identical key signature and note set, just with a different tonal center.
Because these keys differ by only one note (or none, in the case of the relative minor), moving between them tends to sound smooth and natural — which is exactly why so many chord progressions and key changes gravitate toward neighboring wedges on the wheel.
Using the Circle of Fifths for Diatonic Chords
Every major key has seven chords built entirely from its own scale notes, following a fixed pattern of qualities: I (major) – ii (minor) – iii (minor) – IV (major) – V (major) – vi (minor) – vii° (diminished). This pattern holds true in every key, which is why once you know the shape, you can work out the chords for any key on the wheel without memorizing each one individually.
Frequently Asked Questions
What is the Circle of Fifths?
A diagram that arranges all 12 major and minor keys in a circle, each a perfect fifth apart from its neighbors, making key signatures, related keys and chord relationships easy to see at a glance.
Why is it called a circle of fifths?
Moving clockwise from any key to the next lands on the note a perfect fifth above it — C to G, G to D, and so on — and after 12 steps the pattern returns to the starting key, forming a closed circle.
How do you use the Circle of Fifths to find related keys?
The keys immediately clockwise and counterclockwise from any key are its dominant and subdominant, and the key on the inner ring at the same position is its relative minor — these are the keys most closely related and most common to modulate between.
Is this Circle of Fifths tool free to use?
Yes. It runs entirely in your browser and is free to use, with no downloads or account required.