Chord Finder
Pick a root note and a chord quality to instantly see every note in the chord, the interval formula, and a step-by-step breakdown of how the chord is built from the root. Covers triads, suspended, power, seventh, extended, add, sixth, and altered dominant chords - 24 types across all 12 chromatic roots.
How chords are built from intervals
A chord is any group of two or more notes played simultaneously. Chords are defined by the intervals, or gaps in pitch, between the root note and each additional note. Intervals are measured in semitones, the smallest step on a standard keyboard or fretboard. A major triad, for example, stacks a major third (4 semitones) and a perfect fifth (7 semitones) above the root, giving it the characteristic bright, stable sound used in countless songs. The formula 1 - 3 - 5 describes those scale degrees in shorthand. Every chord quality in this calculator is built from exactly this kind of stacking recipe.
Triads vs seventh chords vs extended chords
Triads are three-note chords: major, minor, diminished, and augmented are the four basic types. Adding a fourth note a seventh above the root creates seventh chords - dominant 7th, major 7th, minor 7th, and so on - which are the foundation of jazz harmony. Going further and adding a ninth, eleventh, or thirteenth creates extended chords that sound rich and complex. Add chords (like add9) include an extra note but skip the 7th, keeping a lighter texture than full ninth chords. Sixth chords replace the seventh with a sixth, producing a warm, nostalgic tone common in jazz and vintage pop.
Inversions and voice leading
An inversion rearranges the notes of a chord so a note other than the root is in the bass. Root position has the root at the bottom. First inversion places the third at the bottom. Second inversion places the fifth at the bottom. Third inversion (for four-note chords) places the seventh at the bottom. Inversions do not change the notes in the chord - only their vertical order. In practice, choosing the right inversion lets you move smoothly between chords with minimal motion in each voice, which is called voice leading. A C major chord in root position followed by an F major chord in second inversion, for example, keeps the bottom note the same and moves the other voices by only a step or two.
Enharmonic equivalents and key spelling
Some notes have two names: C# and Db refer to the same pitch but are spelled differently depending on context. This calculator uses sharp spellings for roots like C, G, D, A, E, B, F# and flat spellings for roots like F, Bb, Eb, Ab, Db, Gb. This matches standard music theory practice where you choose the spelling that best fits the key signature. In the key of F major you would use Bb rather than A#, for instance, because F major already uses Bb in its scale. When writing out chords for a song, matching the key spelling keeps notation clean and easier to read.
Common chord types and their formulas
| Category | Chord name | Formula | Semitones |
|---|---|---|---|
| Triad | Major | 1 - 3 - 5 | 0 - 4 - 7 |
| Triad | Minor | 1 - b3 - 5 | 0 - 3 - 7 |
| Triad | Diminished | 1 - b3 - b5 | 0 - 3 - 6 |
| Triad | Augmented | 1 - 3 - #5 | 0 - 4 - 8 |
| Suspended | Suspended 2nd | 1 - 2 - 5 | 0 - 2 - 7 |
| Suspended | Suspended 4th | 1 - 4 - 5 | 0 - 5 - 7 |
| Power | Power Chord (5th) | 1 - 5 | 0 - 7 |
| Seventh | Major 7th | 1 - 3 - 5 - 7 | 0 - 4 - 7 - 11 |
| Seventh | Dominant 7th | 1 - 3 - 5 - b7 | 0 - 4 - 7 - 10 |
| Seventh | Minor 7th | 1 - b3 - 5 - b7 | 0 - 3 - 7 - 10 |
| Seventh | Minor-Major 7th | 1 - b3 - 5 - 7 | 0 - 3 - 7 - 11 |
| Seventh | Diminished 7th | 1 - b3 - b5 - bb7 | 0 - 3 - 6 - 9 |
| Seventh | Half-Diminished 7th (m7b5) | 1 - b3 - b5 - b7 | 0 - 3 - 6 - 10 |
| Seventh | Augmented 7th | 1 - 3 - #5 - b7 | 0 - 4 - 8 - 10 |
| Extended | Major 9th | 1 - 3 - 5 - 7 - 9 | 0 - 4 - 7 - 11 - 2 |
| Extended | Dominant 9th | 1 - 3 - 5 - b7 - 9 | 0 - 4 - 7 - 10 - 2 |
| Extended | Minor 9th | 1 - b3 - 5 - b7 - 9 | 0 - 3 - 7 - 10 - 2 |
| Extended | Dominant 11th | 1 - 3 - 5 - b7 - 9 - 11 | 0 - 4 - 7 - 10 - 2 - 5 |
| Extended | Dominant 13th | 1 - 3 - 5 - b7 - 9 - 13 | 0 - 4 - 7 - 10 - 2 - 9 |
| Add | Add 9 | 1 - 3 - 5 - 9 | 0 - 4 - 7 - 2 |
| Add | Minor Add 9 | 1 - b3 - 5 - 9 | 0 - 3 - 7 - 2 |
| Sixth | Major 6th | 1 - 3 - 5 - 6 | 0 - 4 - 7 - 9 |
| Sixth | Minor 6th | 1 - b3 - 5 - 6 | 0 - 3 - 7 - 9 |
| Altered | Dominant 7b9 | 1 - 3 - 5 - b7 - b9 | 0 - 4 - 7 - 10 - 1 |
| Altered | Dominant 7#9 (Hendrix chord) | 1 - 3 - 5 - b7 - #9 | 0 - 4 - 7 - 10 - 3 |
Interval formulas use scale degrees: b = flat, # = sharp, bb = double flat.
Frequently asked questions
What is the difference between a major and minor chord?
Both chords contain a root and a perfect fifth (7 semitones above the root), but they differ in the middle note. A major chord has a major third (4 semitones above the root), which gives it a bright, happy sound. A minor chord has a minor third (3 semitones above the root), which makes it sound darker and more somber. That single semitone difference completely changes the emotional quality of the chord.
What is a chord inversion?
An inversion puts a note other than the root at the bottom of the chord. The notes stay the same, only their order changes. Root position has the root at the bottom. First inversion has the third at the bottom. Second inversion has the fifth at the bottom. Third inversion (for four-note chords) has the seventh at the bottom. Inversions are used to create smoother movement between chords - called voice leading - and to vary the harmonic texture.
What is a dominant 7th chord and why does it resolve?
A dominant 7th chord (formula: 1 - 3 - 5 - b7) is built on the fifth degree of the major scale. It contains a tritone, the interval between the major third and the minor seventh, which is highly dissonant and creates strong tension. That tension naturally wants to resolve to the tonic chord, which is why the dominant 7th is such a powerful harmonic device. In the key of C major, G7 resolves to C. This resolution is the engine behind most Western music, from Bach to blues.
How many notes does a chord need?
Technically, most definitions require at least three notes for a chord (two notes together are an interval or a dyad). The exception is the power chord, which uses only a root and a perfect fifth - two notes - and is treated as a chord in rock and metal because of how it is used harmonically. Triads have three notes, seventh chords have four, and extended chords can have five or six distinct pitch classes, though in practice some are often omitted to keep voicings playable.
What is the Hendrix chord?
The Hendrix chord is the nickname for the dominant 7#9 chord (formula: 1 - 3 - 5 - b7 - #9). It became famous through Jimi Hendrix's use of it in songs like "Purple Haze." What makes it so distinctive is the simultaneous presence of a major third (giving it a major quality) and an augmented ninth (which is enharmonically equivalent to a minor third), so it sounds neither fully major nor minor. That ambiguity gives it a gritty, bluesy, slightly menacing color.
What is the difference between an add9 chord and a 9th chord?
A 9th chord includes the 7th as well as the 9th: its formula is 1 - 3 - 5 - b7 - 9 (dominant 9th) or 1 - 3 - 5 - 7 - 9 (major 9th). An add9 chord skips the 7th and simply adds the 9th to a basic triad: formula 1 - 3 - 5 - 9. The add9 is lighter and less jazzy than a full 9th chord, and it is widely used in pop and rock for an open, airy texture without the harmonic complexity of the 7th.
Why do some roots use sharps and others use flats?
In standard music theory, each key uses either sharps or flats but not both, to keep notation clean. Keys with sharps on their scale (G, D, A, E, B, F#) prefer sharp note names, while keys built around flat scales (F, Bb, Eb, Ab, Db, Gb) prefer flat names. This calculator automatically applies the preferred spelling for each root. C# and Db are the same pitch, but Db major is spelled with flats, while C# is spelled with sharps - using the wrong spelling would create double sharps or double flats that are harder to read.