How do I read the circle of fifths?

Each step clockwise goes up a perfect fifth and adds a sharp (C → G → D…); each step anticlockwise goes down a fifth and adds a flat (C → F → B♭…). Three neighbouring major keys (such as F, C and G) and their relative minors on the inner ring are exactly the six main diatonic chords of the middle key, which is why nearby keys modulate so smoothly.

Why are some transposed chords written with sharps and others with flats?

Spelling follows the target key’s signature: sharp keys (G, D, A, E…) use sharps and flat keys (F, B♭, E♭…) use flats, and notes in the scale are spelled exactly as in that key, so E♭ major shows A♭ rather than G♯. That keeps the transposed sheet conventional and easy to read.

How do the capo suggestions work?

If the target key is awkward on guitar (E♭ or B♭, for example), put a capo on the suggested fret and play open-chord shapes in C, G, D, A or E. Click a suggestion to see the chart written in those shapes; what you hear will be in the target key.

How accurate is key detection?

The chords in your sheet are compared with the diatonic chords of all 24 major and minor keys, giving extra weight to the first and last chords, which gets most pop songs right. Songs with lots of borrowed chords, key changes or only a few chords may be read as the relative key; just pick the original key by hand.

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🟣Interactive Circle of Fifths - Keys, Chords & Transposer

The circle of fifths is the map most musicians reach for when learning theory, writing songs or working out a tune. The outer ring holds the 12 major keys, the inner ring their relative minors, and the centre ring the number of sharps or flats. Click any segment to see its key signature (drawn on a staff), scale, relative and parallel keys, and switch enharmonic spellings such as B / C♭, F♯ / G♭ and D♭ / C♯. The key’s diatonic chords are listed with Roman numerals as triads or sevenths, with natural or harmonic minor for minor keys (V7, vii°7), and play when clicked. A list of common progressions, including I–V–vi–IV, Pachelbel’s Canon, ii–V–I, the 12-bar blues, 4536251, the Royal Road and the Andalusian cadence, is spelled in the current key and plays on piano or guitar at your tempo. The transposer takes a whole chord sheet (lyric lines are left alone), detects the original key and rewrites every chord in the target key with sharps or flats to match, and suggests capo positions such as “capo 3, play C shapes” along with the chart in those shapes. Finally, the modes table rotates the major scale through all seven modes with step patterns and characteristic notes, and lists the parent key of each mode on the same tonic.

Free · No sign-up · Runs in your browserLast updated: 2026-10-26

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How to use Circle of Fifths

1Click a major key (outer ring) or minor key (inner ring) on the circle
2Read the key signature, scale and diatonic chords, and click chords or progressions to hear them
3To transpose, paste a chord sheet, choose the target key and copy the result or use a capo suggestion

FAQ

How do I read the circle of fifths?: Each step clockwise goes up a perfect fifth and adds a sharp (C → G → D…); each step anticlockwise goes down a fifth and adds a flat (C → F → B♭…). Three neighbouring major keys (such as F, C and G) and their relative minors on the inner ring are exactly the six main diatonic chords of the middle key, which is why nearby keys modulate so smoothly.
Why are some transposed chords written with sharps and others with flats?: Spelling follows the target key’s signature: sharp keys (G, D, A, E…) use sharps and flat keys (F, B♭, E♭…) use flats, and notes in the scale are spelled exactly as in that key, so E♭ major shows A♭ rather than G♯. That keeps the transposed sheet conventional and easy to read.
How do the capo suggestions work?: If the target key is awkward on guitar (E♭ or B♭, for example), put a capo on the suggested fret and play open-chord shapes in C, G, D, A or E. Click a suggestion to see the chart written in those shapes; what you hear will be in the target key.
How accurate is key detection?: The chords in your sheet are compared with the diatonic chords of all 24 major and minor keys, giving extra weight to the first and last chords, which gets most pop songs right. Songs with lots of borrowed chords, key changes or only a few chords may be read as the relative key; just pick the original key by hand.