Circle of Fifths Tool

About This Tool

The Circle of Fifths is the most important diagram in Western music theory. It organizes all 12 major and minor keys in a way that makes their relationships instantly visible. Click any key on the interactive circle above and you'll see its key signature, scale notes, relative minor, parallel minor, and the closest neighboring keys — everything you need to plan a chord progression, write a modulation, or learn a new key.

How the Circle Is Built

Start at C (top, 12 o'clock). Move clockwise by a perfect 5th and you reach G — which has one sharp (F#). Another 5th up brings you to D, which adds C# to make two sharps. Continue and you pass through A, E, B, and F#, accumulating one sharp at each step. Move counterclockwise from C and you reach F, which has one flat (Bb). Another 4th down brings you to Bb (two flats), then Eb, Ab, Db, and Gb. F# and Gb meet at the bottom of the circle as enharmonic equivalents.

Order of Sharps and Flats

The sharps are always added in the same order: F#, C#, G#, D#, A#, E#, B# (mnemonic: "Father Charles Goes Down And Ends Battle"). The flats follow the reverse order: Bb, Eb, Ab, Db, Gb, Cb, Fb ("Battle Ends And Down Goes Charles' Father"). This is why the circle works — each new key adds exactly one accidental in a predictable spot.

Relative and Parallel Minors

Each major key has a relative minor located on the inner ring of the circle. C major and A minor share the same key signature (no sharps or flats), as do G major and E minor (one sharp). The relative minor sits a minor 3rd below the major. The parallel minor, by contrast, shares the tonic with the major key but has its own key signature — C major and C minor both center on C, but C minor has three flats.

Using the Circle for Modulation

Adjacent keys on the circle (one sharp or flat apart) share six of their seven scale notes, making modulation between them very smooth. Movement between distant keys (4-6 sharps or flats apart) is more dramatic and often saved for emotional climaxes. Common modulations include moving up a 5th (to the dominant), down a 5th (to the subdominant), to the relative minor for an emotional dip, or up a half-step for a final-chorus "lift."

Practical Songwriting Applications

When writing a song, start by picking a key that suits the singer's range. Use our Key Signature Finder if you have a melody and need to know its key. Once you know the key, the Chord Progression Builder shows common progressions in that key. Use the Chord Transposer to shift between keys, the Music Interval Calculator to analyze melodic intervals, or the Note Frequency Calculator for exact pitch values.

The Circle and the Cycle of 5ths

The circle of fifths also appears in chord progressions themselves. A "cycle of fifths" movement — where each chord's root is a 5th below the previous (or a 4th above) — is one of the strongest harmonic motions in tonal music. Jazz standards often move through long cycles of fifths: Em7 → A7 → Dm7 → G7 → Cmaj7. Rhythm changes, ii-V-I sequences, and the Coltrane changes all exploit this motion.