Type the chords of any song and this free song key finder estimates its musical key — with the Camelot wheel code for DJs, a harmonic mixing compatibility checker, relative major and minor keys, key signatures, and a capo transposer. Everything runs 100% in your browser; nothing is uploaded.
Paste a chord chart — verse, chorus, or the whole song. Separate chords with spaces, commas or new lines. Example: C G Am F
Click any segment: outer ring = major keys (B codes), inner ring = minor keys (A codes). Numbers run 1–12 around the circle of fifths.
Pick the Camelot code of the track playing now and the track you want to mix into. The checker grades the transition using the six standard harmonic mixing moves.
Pick any key to see its relative and parallel partners, its key signature, all seven diatonic chords with Roman numerals, and its neighbours on the circle of fifths.
Know the shape you like and the key you need? Get the fret.
Every major and minor key lives on the circle of fifths: move one step clockwise and you go up a perfect fifth (C → G → D → A…), adding one sharp each time; move counterclockwise and you go down a fifth (C → F → B♭ → E♭…), adding one flat. Keys next to each other share six of seven notes, which is why progressions rarely wander far around the circle.
Each key owns seven diatonic chords built from its own scale. In any major key the pattern is always I–ii–iii–IV–V–vi–vii° (major, minor, minor, major, major, minor, diminished); in any natural minor key it is i–ii°–III–iv–v–VI–VII. So when you ask "what key is this song in", the honest music-theory answer is: whichever key's diatonic set explains the most chords. That is exactly what the estimator above does — it scores your chord chart against all 24 keys and ranks them. The opening chord gets a small bonus because songs usually start at home, and the results always include the runner-up keys so you can see close calls (very often the relative major and minor pair).
Sharp side clockwise, flat side counterclockwise. Each step adds one accidental to the key signature chart below.
| Key | Key signature | Camelot |
|---|---|---|
| Clockwise — sharps | ||
| C major | — | 8B |
| G major | 1 ♯ | 9B |
| D major | 2 ♯ | 10B |
| A major | 3 ♯ | 11B |
| E major | 4 ♯ | 12B |
| B major | 5 ♯ | 1B |
| F# major | 6 ♯ | 2B |
| Counterclockwise — flats | ||
| C major | — | 8B |
| F major | 1 ♭ | 7B |
| Bb major | 2 ♭ | 6B |
| Eb major | 3 ♭ | 5B |
| Ab major | 4 ♭ | 4B |
| Db major | 5 ♭ | 3B |
The Camelot wheel is simply the circle of fifths re-numbered for DJs: 24 codes, 1A–12A for minor keys and 1B–12B for major keys. 8B is C major, 8A is A minor, and the numbers climb a fifth at a time. It exists so you can mix in key without memorizing key signatures: codes that sit next to each other on the wheel blend smoothly, codes far apart clash. The full mapping doubles as a key signature chart:
| Camelot | Key | Mode | Key signature | Relative key |
|---|---|---|---|---|
1A | G# minor | minor | 5 ♯ | B major |
1B | B major | major | 5 ♯ | G# minor |
2A | D# minor | minor | 6 ♯ | F# major |
2B | F# major | major | 6 ♯ | D# minor |
3A | Bb minor | minor | 5 ♭ | Db major |
3B | Db major | major | 5 ♭ | Bb minor |
4A | F minor | minor | 4 ♭ | Ab major |
4B | Ab major | major | 4 ♭ | F minor |
5A | C minor | minor | 3 ♭ | Eb major |
5B | Eb major | major | 3 ♭ | C minor |
6A | G minor | minor | 2 ♭ | Bb major |
6B | Bb major | major | 2 ♭ | G minor |
7A | D minor | minor | 1 ♭ | F major |
7B | F major | major | 1 ♭ | D minor |
8A | A minor | minor | — | C major |
8B | C major | major | — | A minor |
9A | E minor | minor | 1 ♯ | G major |
9B | G major | major | 1 ♯ | E minor |
10A | B minor | minor | 2 ♯ | D major |
10B | D major | major | 2 ♯ | B minor |
11A | F# minor | minor | 3 ♯ | A major |
11B | A major | major | 3 ♯ | F# minor |
12A | C# minor | minor | 4 ♯ | E major |
12B | E major | major | 4 ♯ | C# minor |
Harmonic mixing is the DJ craft of choosing the next track by key, not just by BPM. Once every track in your library is tagged with its Camelot code, these are the six moves that work:
| Move | Code change | Example | Effect |
|---|---|---|---|
| Perfect match | same code | 8A → 8A | Zero harmonic risk; the smoothest blend |
| Energy boost | +1 number, same letter | 8A → 9A | Up a perfect fifth; lifts the room |
| Energy drop | −1 number, same letter | 8A → 7A | Down a fifth; eases energy gracefully |
| Mood change | same number, A↔B | 8A → 8B | Relative major/minor flip; same notes, new mood |
| Diagonal mix | ±1 number + letter flip | 8A → 9B | Spicy but musical when the groove fits |
| Energy jump | ±2 numbers, same letter | 8A → 10A | Bold jump; match energy levels carefully |
Use the compatibility checker tab to grade any pair before you commit to it in a live set.
Relative major and minor keys share a key signature and all seven notes — only the tonal center moves. C major's relative minor is A minor (three semitones down); G major's is E minor. This is the single biggest source of "two possible keys" results: a I–V–vi–IV song in C uses exactly the same chords as a i–VI–III–VII song in A minor. The estimator breaks the tie toward whichever tonic the song opens on, and the Relative keys tab shows both partners plus the parallel key (same tonic, opposite mode) for every key.
The complete chord key compatibility reference. Find your progression's chords in a row — if they all appear, that is almost certainly the key. One chord missing from the row is usually a borrowed chord (the ♭VII, e.g. B♭ in C major, is the most common guest).
| Key | I | ii | iii | IV | V | vi | vii° |
|---|---|---|---|---|---|---|---|
C major 8B | C | Dm | Em | F | G | Am | B° |
G major 9B | G | Am | Bm | C | D | Em | F#° |
D major 10B | D | Em | F#m | G | A | Bm | C#° |
A major 11B | A | Bm | C#m | D | E | F#m | G#° |
E major 12B | E | F#m | G#m | A | B | C#m | D#° |
B major 1B | B | C#m | D#m | E | F# | G#m | A#° |
F# major 2B | F# | G#m | A#m | B | C# | D#m | E#° |
F major 7B | F | Gm | Am | Bb | C | Dm | E° |
Bb major 6B | Bb | Cm | Dm | Eb | F | Gm | A° |
Eb major 5B | Eb | Fm | Gm | Ab | Bb | Cm | D° |
Ab major 4B | Ab | Bbm | Cm | Db | Eb | Fm | G° |
Db major 3B | Db | Ebm | Fm | Gb | Ab | Bbm | C° |
A song key finder tells you the musical key a song is written in — for example C major or A minor. This page is a theory-based key finder: type the song's chords and it estimates the key using the circle of fifths, then shows the Camelot wheel code, the relative major or minor key, and which chords fit. It does not analyze audio files.
It compares every chord you type against the diatonic chords of all 24 major and minor keys. Exact matches score highest, borrowed chords score less, and chromatic chords score below zero; the opening chord gets a small tonic bonus because songs usually start at home. The three best-scoring keys are shown with a confidence percentage. Because this is pure music theory — no audio analysis — it answers "what key is this song in" from a chord chart in seconds, with no uploads and no signup.
Very good for mainstream diatonic music — pop, rock, folk and EDM built on progressions like I–V–vi–IV routinely score 90–100% confidence. It gets weaker with jazz (lots of secondary dominants), modal songs, heavy borrowed chords, or songs that change key halfway through. That is why the tool always shows its top 3 candidates and the chord-by-chord reasoning: check whether the losers make musical sense too, and let your ears decide.
The Camelot wheel is the DJ-friendly numbering of the circle of fifths: 24 codes, 1A–12A for minor keys and 1B–12B for major keys. 8A is A minor, 8B is C major, and so on around the wheel. DJs use it for harmonic mixing because compatible codes sit next to each other — you can mix in key without memorizing key signatures. Click any segment of the interactive wheel above to see a key's code, signature, diatonic chords and mix partners.
The letter tells you the mode: A codes are minor keys, B codes are major keys. The number tells you the position on the wheel. Codes that share a number — like 8A and 8B — are relative major and minor pairs (A minor and C major): same notes, different home. Moving +1 or −1 in number moves a perfect fifth around the circle of fifths.
Harmonic mixing means choosing the next track so its key blends with the current one instead of clashing. The six standard moves: stay on the same code (perfect match), go +1 in number (energy boost), −1 (energy drop), flip A↔B on the same number (mood change between relative major and minor), move ±1 with a letter flip (diagonal mix), or jump ±2 (energy jump). The compatibility checker above grades any pair of codes — use it to plan a set that flows.
Relative major and minor keys share the same key signature and the same seven notes — only the tonal center differs. C major's relative minor is A minor; G major's is E minor. That is why progressions like Am–F–C–G can read as either key: every chord is diatonic to both. The estimator breaks the tie with the opening chord and the V–I cadence, and always lists the relative key next to each result.
Two strong candidates usually means you found a relative major/minor pair (for example C major vs A minor) or two keys a fifth apart sharing most chords. Look at the chord-by-chord table: if every chord is diatonic to both, check which chord the song starts and ends on, and listen for the V–I resolution — D→G points at G major, B7→Em points at E minor. Three candidates with low confidence usually means borrowed chords or a mid-song key change.
A capo on fret N raises the concert pitch of everything you play by N semitones: a G shape with capo 2 sounds as A. The song's real key is the concert key, not the shape key — so if the band says "it's in A" and the guitarist plays G shapes, there is a capo on fret 2. Use the capo transposer above three ways: shape + capo → concert pitch, transpose a whole progression, or find which fret turns your favourite shape into the target key.
No — deliberately. This tool covers the 12 major and 12 natural minor keys, which is what ~95% of popular songs use. Modes like Dorian, Mixolydian or Phrygian share the notes of a parent major key, so a Dorian song will simply estimate as its parent key (D Dorian reads as C major). If you write modal music, treat the result as "parent key" and shift your thinking one step around the wheel.
Audio key detectors analyze the actual sound file (chroma vectors matched against key profiles) and work when you have a recording but no chord chart. This tool does the reverse: it works from a chord chart when you have no audio — or when you want to understand WHY a song is in a key, not just what the answer is. They complement each other: detect from audio, then verify and explore here with the wheel, the compatibility chart and the relative keys.
C major contains C, Dm, Em, F, G, Am and B diminished — the I ii iii IV V vi vii° pattern every major key follows. The full chord key compatibility table below lists all seven diatonic chords for every major key, so you can check any progression at a glance or spot the one borrowed chord that breaks the pattern.
They answer different questions. A key finder tells you the song's musical key (C major, A minor, 8B...) for harmonic mixing and transposing; a tap-tempo tool measures the speed (BPM). If you need tempo, use our dedicated tempo tools: BPM Tap Calculator, Tempo Detector and Tempo Tapper — this page stays focused on key, so it links to them instead of duplicating them.
No. To find the key of a song, paste a chord chart (for example: C G Am F) and hit Find key — the tool explains each result in plain words, with the Camelot code for DJs and the chord-by-chord reasoning for the curious. Everything runs 100% in your browser: your chords are never uploaded, stored or tracked.
More music tools:
Need speed instead of key? BPM Tap Calculator · Tempo Detector · Tempo Tapper — tap tempo and BPM detection live there, not here.
Building progressions from scratch? Chord Lab constructs 101 chord types with frequencies, voicings and playback.