Circle of Fifths — keys, signatures & relatives
Explore the circle of fifths interactively: key signatures, relative minors and neighbouring keys.
🔒 Runs entirely in your browser. Your input and output are never sent to a server or stored — fully private.
Tap any key on the circle to explore it.
About this tool
The interactive circle of fifths arranges all twelve keys so that neighbours sit a perfect fifth apart, making it easy to see each key's signature, its relative minor and the chords that naturally belong together. Click around the circle to explore key relationships for composing, transposing or understanding why certain chord changes sound so smooth. It all runs in your browser.
Frequently asked questions
What is the circle of fifths used for?
It is a map of how keys relate: moving clockwise adds a sharp, moving anticlockwise adds a flat, and keys next to each other share most of their notes. Songwriters use it to find chords that fit a key and to plan smooth changes of key.
How do I find the relative minor?
Every major key has a relative minor that shares the same key signature, shown just inside it on the circle — C major and A minor, for example. The two rings let you read each major-and-minor pair at a glance.
How do key signatures work on the circle?
Starting from C at the top, each step clockwise adds one sharp and each step anticlockwise adds one flat, so a key's position tells you exactly how many sharps or flats it has. The tool shows the signature for whichever key you select.