Reverse Chord Finder – Name That Chord from Notes

A Reverse Chord Finder (also called a chord identifier or chord namer) is a tool that analyzes a set of musical notes and determines which chord(s) they form. Instead of looking up a chord by name, you provide the actual notes — and the tool works backward to identify the chord name, type, and structure. This is especially useful when you're experimenting on a keyboard, analyzing sheet music, or trying to name a chord you've discovered by ear.

At minimum, 2 notes are needed to identify a musical interval (such as a perfect fifth or major third). For full chord identification, 3 or more notes are recommended. Three notes can form a basic triad (major, minor, diminished, or augmented). Four notes typically form seventh chords (major 7th, minor 7th, dominant 7th, etc.). Five or more notes may form extended chords like 9th, 11th, or 13th chords. The tool works best with 3–5 distinct notes.

Triads are three-note chords that form the foundation of Western harmony. There are four basic types: Major triad (root + major third + perfect fifth, e.g., C–E–G), Minor triad (root + minor third + perfect fifth, e.g., C–E♭–G), Diminished triad (root + minor third + diminished fifth, e.g., C–E♭–G♭), and Augmented triad (root + major third + augmented fifth, e.g., C–E–G♯). Triads are the building blocks for more complex chords.

The key difference lies in the third of the chord. A major chord uses a major third (4 semitones above the root), creating a bright, happy sound. A minor chord uses a minor third (3 semitones above the root), producing a darker, sadder quality. For example, C Major = C–E–G, while C Minor = C–E♭–G. The fifth is the same in both (7 semitones above the root).

A chord inversion occurs when a note other than the root is the lowest note. Root position: the root is the lowest note (C–E–G for C Major). First inversion: the third is the lowest note (E–G–C). Second inversion: the fifth is the lowest note (G–C–E). For seventh chords, a third inversion has the seventh as the lowest note. This tool automatically detects the root and identifies chords regardless of inversion — so E–G–C will correctly be identified as C Major.

Seventh chords are four-note chords that add a seventh interval above the root to a triad. Common types include: Major 7th (major triad + major 7th, e.g., C–E–G–B, written Cmaj7), Minor 7th (minor triad + minor 7th, e.g., C–E♭–G–B♭, written Cm7), Dominant 7th (major triad + minor 7th, e.g., C–E–G–B♭, written C7), Half-diminished 7th (diminished triad + minor 7th, e.g., C–E♭–G♭–B♭, written Cm7♭5 or Cø), and Diminished 7th (diminished triad + diminished 7th, e.g., C–E♭–G♭–B♭♭, written C°7).

Suspended chords replace the third with either a second or fourth scale degree, creating a floating, unresolved sound. Sus4 replaces the third with a perfect fourth (e.g., C–F–G instead of C–E–G). Sus2 replaces the third with a major second (e.g., C–D–G). These chords are neither major nor minor because the third — which determines major/minor quality — is absent. They're commonly used to create tension before resolving to a standard triad.

Diminished chords are built from stacked minor thirds. A diminished triad (e.g., C–E♭–G♭) has a root, minor third, and diminished fifth (6 semitones above root). A diminished 7th adds another minor third (9 semitones). Augmented chords are built from stacked major thirds. An augmented triad (e.g., C–E–G♯) has a root, major third, and augmented fifth (8 semitones). Augmented chords are symmetrical — C aug, E aug, and G♯ aug all contain the same notes (enharmonically).

Yes. This tool recognizes extended chords including 9th, 11th, and 13th chords, as well as altered chords, add9, 6th chords, and more. Extended chords contain additional notes stacked beyond the seventh (the 9th is the 2nd scale degree an octave up, the 11th is the 4th, and the 13th is the 6th). When you select 5 or more notes, the tool searches for these extended voicings. Jazz chords like Cmaj9, Dm11, or G13 will be identified when their constituent notes are selected.

Enharmonic equivalence means the same pitch can be written with different note names — for example, C♯ and D♭ sound identical on a piano. This tool primarily uses sharp-based naming (C♯, D♯, F♯, G♯, A♯), but many chords have valid alternative names. For instance, C♯ Major (C♯–E♯–G♯) is enharmonically equivalent to D♭ Major (D♭–F–A♭). The tool prioritizes the most common and practical name, and notes common enharmonic alternatives in the results when applicable.

Identifying chords by ear takes practice but follows a systematic approach: 1) Listen for the bass note (lowest pitch) — this is often the root. 2) Determine the chord quality — does it sound happy (major) or sad (minor)? 3) Count the distinct notes you hear. 4) Listen for extensions — does it have a seventh? A ninth? 5) Use this tool as a reference: play the notes you hear on the piano keys above and confirm the chord name. Over time, your ear will learn to recognize common patterns. Start with basic triads before moving to seventh chords and beyond.

A power chord (also called a fifth chord) is a two-note chord consisting of the root and perfect fifth — for example, C–G. It contains no third, so it's neither major nor minor, giving it a neutral, powerful sound. Power chords are extremely common in rock, metal, and punk music, often played with distortion on electric guitar. They're typically written as C5, D5, E5, etc. This tool will identify a perfect fifth interval as a power chord when exactly two notes are selected.