🎼 Key Signature Finder
Choose a major or minor key to see its key signature — the number of sharps or flats, exactly which notes, and its relative key.
G major
Signature
1 sharp
Accidentals
F♯
Relative minor
E minor
Key signatures follow the circle of fifths: each step clockwise adds a sharp (in the order F♯ C♯ G♯ D♯ A♯ E♯ B♯), each step anticlockwise adds a flat (B♭ E♭ A♭ D♭ G♭ C♭ F♭). Every major key shares its signature with a relative minor a minor third below. 🔒 In your browser.
How the key signature finder works
Key signatures follow the circle of fifths. Starting from C major (no sharps or flats), each move clockwise up a fifth adds one sharp, applied in the fixed order F♯ C♯ G♯ D♯ A♯ E♯ B♯; each move anticlockwise down a fifth adds one flat, in the order B♭ E♭ A♭ D♭ G♭ C♭ F♭. Every major key shares its signature with a relative minor a minor third below (C major / A minor), so the tool shows the sharps or flats, the exact accidental notes, and the relative key.
The relative minor uses the same notes and signature as its major key but centres on a different tonic. Don't confuse it with the parallel minor (same tonic, different signature — C major vs C minor), which differs by three flats.
Frequently asked questions
How many sharps or flats does a key have?
It depends on the key. C major/A minor have none; each step clockwise round the circle of fifths adds a sharp (G major = 1, D = 2, A = 3…) and each step the other way adds a flat (F = 1, B♭ = 2, E♭ = 3…). Pick a key to see the exact count.
What order do sharps and flats go in?
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♭. A key with three sharps therefore has F♯, C♯ and G♯.
What is a relative minor?
The minor key that shares a major key's exact key signature, built on the sixth degree — a minor third below the major tonic. C major's relative minor is A minor; both use no sharps or flats.
What is the circle of fifths?
A diagram arranging the twelve keys by ascending fifths. Moving clockwise adds sharps, anticlockwise adds flats, and opposite keys are a tritone apart. It's the map that ties every key signature together.
What's the difference between relative and parallel minor?
A relative minor shares the major key's signature but has a different tonic (C major / A minor). A parallel minor shares the tonic but has a different signature (C major / C minor, which differs by three flats).