Music tools
Circle of fifths
Click any key on the wheel to see its key signature, relative minor, and diatonic chords. Everything runs in your browser.
How it works
The circle of fifths arranges the twelve keys so that each step clockwise goes up a fifth and adds a sharp, while each step counter-clockwise goes down a fifth and adds a flat. It is the single most useful map in music theory: neighbouring keys are closely related, the number of sharps or flats is easy to read off, and each major key sits next to its relative minor. Click any key on the wheel to see its key signature, its relative minor, and the chords built from its scale.
Use it to find a key signature, to spot which keys are a comfortable step away for modulation, or to see why certain chords belong together. The whole wheel is drawn and computed in your browser, so nothing is uploaded.
Example. Click G and the wheel shows one sharp (F#), the relative minor E minor, and the diatonic chords G, Am, Bm, C, D, Em, and F#dim. One step clockwise to D adds a second sharp (C#).
FAQ
What is the circle of fifths used for?
For reading key signatures, finding the relative major or minor of a key, choosing keys that are closely related for modulation, and understanding chord relationships. It lays all twelve keys out in the order that makes those relationships clear.
Why is it called "fifths"?
Because each move clockwise around the circle is an interval of a perfect fifth - C to G to D and so on - which is also the order in which sharps are added to the key signature. Going the other way, by fourths, adds flats.
How do I find a relative minor?
Every major key shares its key signature with a minor key a minor third below, its relative minor. The circle shows that pairing for each position, so the relative minor of C is A minor, of G is E minor, and so on.
Does it run offline?
Yes. The wheel and its key data are generated in your browser, so the tool works offline and nothing is uploaded.