Chord Formulas
A chord formula lists a chord's notes as numbers from the major scale of its root. A major chord is 1 3 5; a minor chord is 1 ♭3 5, with the 3rd a half step lower. So C major is C E G, and C minor is C E♭ G.
How chord formulas work
Take the major scale that starts on the chord’s root, and number its notes 1 to 7. A formula picks notes by number:
| Degree | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
|---|---|---|---|---|---|---|---|
| C major scale | C | D | E | F | G | A | B |
- 1 3 5 picks C, E and G: C major.
- ♭ means one half step lower. 1 ♭3 5 is C, E♭, G: C minor.
- ♯ means one half step higher. 1 3 ♯5 is C, E, G♯: C augmented.
Triads: three-note chords
| Chord | Formula | Symbol | From C | Built from |
|---|---|---|---|---|
| Major | 1 3 5 | C | C E G | major 3rd + minor 3rd |
| Minor | 1 ♭3 5 | Cm | C E♭ G | minor 3rd + major 3rd |
| Diminished | 1 ♭3 ♭5 | C° or Cdim | C E♭ G♭ | minor 3rd + minor 3rd |
| Augmented | 1 3 ♯5 | C+ or Caug | C E G♯ | major 3rd + major 3rd |
| Sus2 | 1 2 5 | Csus2 | C D G | the 3rd replaced by the 2nd |
| Sus4 | 1 4 5 | Csus4 | C F G | the 3rd replaced by the 4th |
The 3rd decides whether a chord is major or minor. The 5th is the same in both (seven half steps above the root), and changing it makes a diminished or augmented chord. To hear the difference, choose any note on the online pitch pipe and press Play the chord, first major, then minor.
Another way to see it: stacked 3rds
Every triad above, except the sus chords, is two 3rds stacked on top of each other. Counting half steps:
| Triad | Bottom 3rd | Top 3rd |
|---|---|---|
| Major | 4 (major 3rd) | 3 (minor 3rd) |
| Minor | 3 (minor 3rd) | 4 (major 3rd) |
| Diminished | 3 | 3 |
| Augmented | 4 | 4 |
That’s why a triad on the staff looks like a snowman: three notes on three lines in a row, or three spaces.
How to build any chord
- Write the major scale of the root. For D: D E F♯ G A B C♯.
- Pick the notes by number. 1 3 5 is D, F♯, A: D major.
- Apply any ♭ or ♯. 1 ♭3 5 lowers F♯ to F: D, F, A is D minor.
Seventh chords: four-note chords
A seventh chord adds a fourth note, a 7th above the root, to a triad.
| Chord | Formula | Symbol | From C |
|---|---|---|---|
| Dominant 7th | 1 3 5 ♭7 | C7 | C E G B♭ |
| Major 7th | 1 3 5 7 | Cmaj7 or CΔ7 | C E G B |
| Minor 7th | 1 ♭3 5 ♭7 | Cm7 | C E♭ G B♭ |
| Half-diminished 7th | 1 ♭3 ♭5 ♭7 | Cø7 or Cm7♭5 | C E♭ G♭ B♭ |
| Diminished 7th | 1 ♭3 ♭5 ♭♭7 | C°7 or Cdim7 | C E♭ G♭ B♭♭ |
A plain 7 in a chord symbol (C7) means the dominant 7th, with the lowered 7th. maj7 means the 7th from the major scale. In the diminished 7th, ♭♭7 is a double flat: B lowered two half steps, the same piano key as A.
Reading chord symbols
| Symbol | Means |
|---|---|
| C | C major |
| Cm or C− | C minor |
| C° or Cdim | C diminished |
| C+ or Caug | C augmented |
| C7 | C dominant 7th |
| Cmaj7 | C major 7th |
| Cm7 | C minor 7th |
Learn it step by step
Trebly’s Major and Minor Chords lesson has you build triads on the staff, count half steps on the keyboard to tell major from minor, and name chords, including ones where a sharp or flat flips the chord. Chords in a key shows which chords belong together. To see every major and minor chord on the keys, print the free piano chord chart. To see and hear any chord on this page on piano, guitar or ukulele, look it up in the chord finder. Have the notes but not the name? Tap them into the chord identifier.