Circle of Fifths

This interactive circle of fifths turns the classic music-theory wheel into something you can click, read and hear. Choose any of the 30 major and minor keys and the tool draws its key signature on a treble staff, highlights the scale on a piano keyboard, lists every diatonic chord with roman numerals, names the closely related keys you can modulate to, and plays common chord progressions in that key straight in your browser. If you only know the chords of a song, it can also tell you which key the song is in, and it prints a clean circle of fifths chart for your music stand or classroom wall.

How to Use This Tool

1. Choose a key: pick any of the 30 major and minor keys from the Musical Key menu, or click a key straight on the wheel.
2. Read the key signature: the treble staff shows the sharps or flats in their correct written order and position.
3. Study the scale and chords: the piano diagram highlights every note in the key, and the chord cards give roman numerals, note spellings, and harmonic function.
4. Listen: press any play button to hear the scale, a single chord, or a full progression in that key.
5. Modulate: click any of the closely related keys to jump straight to it and compare.
6. Find a song’s key: type its chords into Find the Key from Chords and open the best match.
7. Print: press Print chart for a one-page circle of fifths chart, or save it as a PDF.

What Is the Circle of Fifths?

The circle of fifths is a map of how the twelve keys relate to one another. Starting from C at the top, every step clockwise moves up a perfect fifth (C → G → D → A …) and adds one sharp to the key signature. Every step counter-clockwise moves down a fifth, which is the same as up a fourth (C → F → B♭ → E♭ …), and adds one flat. After twelve steps you arrive back where you started, which is why the diagram closes into a circle.

The reason this ordering matters is simple: neighbouring keys share almost all of their notes. C major and G major differ by exactly one note (F versus F♯). That single-note difference is what makes movement around the circle sound smooth, and it is why the circle is used for choosing chord progressions, planning modulations, transposing parts, and memorising key signatures.

How to Read the Wheel

• Outer ring — major keys. C sits at the top, sharps increase clockwise, flats increase counter-clockwise.
• Inner ring — relative minors. Each minor key shares the exact key signature of the major key directly outside it.
• Outside labels — accidental count. The small label beyond each position tells you how many sharps or flats that signature carries.
• Bottom of the circle — enharmonic keys. At five, six and seven accidentals the sharp and flat spellings meet: B = C♭, F♯ = G♭, and C♯ = D♭ sound identical.

Key Signature Order: Sharps and Flats

Accidentals are never added randomly. Sharps always appear in the order F C G D A E B, and flats appear in exactly the reverse order, B E A D G C F. A key with three sharps therefore always has F♯, C♯ and G♯ — never any other combination.

Two quick tricks for reading a signature at sight:

• Sharp keys: the tonic is one semitone above the last sharp. Three sharps end on G♯, so the key is A major.
• Flat keys: the tonic is the second-to-last flat. Four flats are B♭ E♭ A♭ D♭, so the key is A♭ major. (One flat, F major, is the exception you memorise.)

Key Signature Chart: All 15 Major and Minor Keys

Diatonic Chords and Roman Numerals

Stack every other note of a scale and you get the seven chords that belong to the key. Their qualities never change, which is why roman numerals are such a compact way to describe a song: capital numerals are major chords, lower-case are minor, and a small circle marks a diminished chord.

In a minor key the fifth chord is naturally minor, which gives a weak pull back to the tonic. Raising the seventh degree by a semitone produces the harmonic minor scale and turns that chord into a major V, restoring the strong leading-tone resolution. This tool shows the natural-minor chords and uses the harmonic V wherever a cadence needs it.

Using the Circle for Modulation

The five closely related keys are the two neighbours on the circle plus the relative minor or major of all three positions. Their signatures differ from the home key by at most one accidental, so they share six of seven notes and a modulation to them needs no preparation at all. Move further around the circle and the shift becomes progressively more dramatic — jumping to the opposite side is the harmonic equivalent of changing the scenery entirely.

A practical trick: find a pivot chord that exists in both keys. Moving from C major to G major, the chords C, Em, G and Am all belong to both keys, so playing one of them lets you slip across the seam without the listener noticing.

Common Chord Progressions

• I – V – vi – IV — the four-chord pop loop behind an enormous number of hit songs.
• ii – V – I — the jazz cadence; the roots fall by a fifth each time, which is a straight walk anticlockwise around the circle.
• I – vi – IV – V — the 1950s doo-wop progression.
• i – VI – III – VII — the epic minor loop used across film scores and rock.
• i – VII – VI – V — the Andalusian cadence, a descending flamenco figure.

Notice how many of these move by fifths. Root motion down a perfect fifth is the strongest progression in tonal music, and the circle of fifths is literally a picture of it.

How to Find the Key of a Song

Every key owns seven chords: three major, three minor and one diminished. In C major they are C, Dm, Em, F, G, Am and B°. If all the chords of a song sit inside one of these sets, the song is almost certainly in that key or in its relative minor, which uses the same chords. That is what Find the Key from Chords checks: it compares your chords with the chord set of all 30 keys and ranks the keys that hold the most of them.

• Look at the first and last chord. Songs usually start or end on the home chord. G D Em C fits both G major and E minor, but it starts on G, so G major is the better answer.
• Minor songs borrow the major V. A song in A minor often uses E major instead of E minor, because it pulls more strongly back to Am. The finder accepts that chord in minor keys.
• One chord outside the key is normal. Pop and rock borrow chords all the time (B♭ in a song in C, for example). The finder lists them so you can see which ones they are.
• Sevenths and slash chords are fine. G7, Cmaj7, Am7 and D/F♯ are read as G, C, Am and D.

Printable Circle of Fifths Chart

Press Print chart under the wheel for a one-page chart: all twelve major keys on the outer ring, their relative minors on the inner ring, the number of sharps or flats for each position, the order of sharps and flats, and a table of every key signature. It is sized for A4 and US Letter paper. To keep a copy on a phone or tablet, choose Save as PDF as the printer.

Frequently Asked Questions

What is the circle of fifths?

The circle of fifths is a diagram that arranges the twelve musical keys so that each step clockwise moves up a perfect fifth and adds one sharp to the key signature, while each step counter-clockwise moves down a fifth and adds one flat. Neighbouring keys share almost all of their notes, which makes the circle a map of how keys relate to one another.

How do I read a key signature from the circle of fifths?

Count the steps from C at the top. Each clockwise step adds one sharp, so G has one sharp, D has two, and A has three. Each counter-clockwise step adds one flat, so F has one flat, B♭ has two, and E♭ has three. Sharps are always added in the order F C G D A E B, and flats in the reverse order B E A D G C F.

What is a relative minor?

A relative minor is the minor key that shares the exact same key signature as a major key. Its tonic sits three semitones below the major tonic, which is the sixth degree of the major scale. On the circle of fifths the relative minor sits on the inner ring at the same clock position, so A minor pairs with C major and E minor pairs with G major.

What are closely related keys?

Closely related keys are the five keys whose signatures differ from the home key by at most one accidental: the keys one step clockwise and one step counter-clockwise on the circle, plus all three of their relative minors or majors. Because they share six of seven notes with the home key, you can modulate to them without any preparation, which is why most classical and pop modulations move to a neighbour on the circle.

Why do F♯ major and G♭ major sound the same?

They are enharmonic keys: the same twelve pitches spelled two different ways. F♯ major writes six sharps and G♭ major writes six flats, and on a piano the notes sound identical. The circle of fifths closes at that point, which is why the bottom of the wheel shows both spellings. Composers pick whichever spelling is easier to read for the instruments involved.

What is the difference between the circle of fifths and the circle of fourths?

They are the same diagram read in opposite directions. Moving clockwise raises the tonic by a perfect fifth, and moving counter-clockwise raises it by a perfect fourth. Jazz musicians often call it the circle of fourths because root motion down a fifth, which is the same as up a fourth, drives the ii–V–I progression.

How do I find the key of a song from its chords?

Type the chords into Find the Key from Chords, for example G D Em C, and the tool lists the keys whose chords contain them, best fit first. A song that starts or ends on a chord is usually in that chord’s key, so when two keys fit equally well, as G major and E minor do for G D Em C, the tool ranks the one whose tonic opens or closes your list first. Chords that fit no key are usually borrowed chords, which are common in pop and rock.

Can I print a circle of fifths chart?

Yes. Press Print chart under the wheel to print a one-page chart with all twelve major keys, their relative minors and the number of sharps or flats in each key signature, plus the order of sharps and flats. Choose Save as PDF in the print dialog to keep a copy on your phone or tablet.

Additional Resources

• Circle of Fifths - Wikipedia
• Key Signature - Wikipedia
• Relative Key - Wikipedia