How to use it
- Click a major key on the outer ring or a minor key on the inner ring.
- Read the key signature and see it on the staff.
- Play the scale and click the triads to hear them.
- Try the quiz to test yourself.
How the circle works
The outer ring holds the 12 major keys and the inner ring their relative minors, which share the same key signature. Starting from C major at the top, each step clockwise goes up a perfect fifth and adds one sharp: G (1♯), D (2♯), A (3♯), E (4♯), B (5♯), F♯ (6♯). Each step counterclockwise goes up a fourth and adds one flat: F (1♭), B♭ (2♭), E♭ (3♭), A♭ (4♭), D♭ (5♭), G♭ (6♭).
At the bottom three spots carry two names because the keys sound the same but are written differently: B = C♭, F♯ = G♭ and C♯ = D♭. Those pairs are listed in the Enharmonic key pairs box, and the enharmonic button jumps between them.
Key signatures at a glance
| Major | Relative minor | Sharps or flats |
|---|---|---|
| C | A minor | none |
| G | E minor | F♯ |
| D | B minor | F♯ C♯ |
| A | F♯ minor | F♯ C♯ G♯ |
| E | C♯ minor | F♯ C♯ G♯ D♯ |
| B | G♯ minor | F♯ C♯ G♯ D♯ A♯ |
| F | D minor | B♭ |
| B♭ | G minor | B♭ E♭ |
| E♭ | C minor | B♭ E♭ A♭ |
| A♭ | F minor | B♭ E♭ A♭ D♭ |
| D♭ | B♭ minor | B♭ E♭ A♭ D♭ G♭ |
Sharps always appear in the order F C G D A E B and flats in the reverse order, B E A D G C F. The tool draws the signature on a treble or bass staff in the standard positions, so you can learn exactly where each sharp or flat sits.
Scale, chords and related keys
Below the circle you get the chosen key's major or natural minor scale, which you can play, and the seven triads built on its degrees with Roman numerals. The three primary chords, I, IV and V (tonic, subdominant and dominant), are highlighted: in G major they're G, C and D. Click any triad to hear it.
The neighbors on the circle are the most closely related keys. The dominant is one step clockwise, the subdominant one step counterclockwise, and the relative key sits directly inside or outside. Songs most often modulate to these keys, and chord progressions like ii–V–I move counterclockwise around the circle. In minor keys the tool also shows the raised seventh of harmonic minor, which turns the minor v chord into a major V.
Practice and memory tricks
The quiz shows a random major or minor key and asks how many sharps or flats it has; click the answer and the tool tells you if you're right, with a link to show it on the circle.
Two classic shortcuts help:
- For sharp keys, the last sharp is one half step below the key name: in E major the last sharp is D♯.
- For flat keys, the second-to-last flat is the key name: with B♭ E♭ A♭ the key is E♭ major. F major, with one flat, is the one to memorize.
Use the scale finder to explore modes on any root, and the chord transposer to move a song to a neighboring key.
Frequently asked questions
What is the circle of fifths used for?
It shows the key signature of every major and minor key, which keys are closely related, and the order of sharps and flats. Songwriters use it to find chords that fit together and to plan key changes.
How many sharps does E major have?
Four: F♯, C♯, G♯ and D♯. Its relative minor, C♯ minor, has the same four.
What is a relative minor?
The minor key that shares a major key's signature. It starts on the major scale's sixth degree: A minor is the relative minor of C major.
Why do some keys have two names?
F♯ major and G♭ major sound the same on the piano but are written with six sharps or six flats. These are enharmonic keys.
What is the circle of fourths?
The same circle read counterclockwise. Each step goes up a perfect fourth and adds a flat.
Last updated: November 12, 2026