Augmented chord: formula, notes and sound
An augmented chord is two stacked major thirds (0-4-8 semitones). Hear its dreamy, unresolved sound, see it on every root and test your ear.
An augmented chord (augmented triad) is the root, a major third (4 semitones) and an augmented fifth (8 semitones): two major thirds stacked. C augmented is C, E and G sharp. It sounds suspended, dreamy and unresolved, like a question mark.
Listen to Caug
C E G♯
What is the formula of a augmented chord?
| Chord tone | Interval from the root | Semitones | In C |
|---|---|---|---|
| Root | root | 0 | C |
| Third | major third | 4 | E |
| Fifth | augmented fifth | 8 | G♯ |
Formula: 0-4-8 semitones. Written Caug, C+.
What does a augmented chord sound like?
Shimmering and uneasy, as if floating. Because it divides the octave into three equal major thirds, it has no clear root by ear.
How to recognise it by ear
- Start from a major chord and raise the top note a semitone: C E G becomes C E G♯.
- C+ , E+ and G♯+ contain the same three notes (enharmonically), so there are only four different augmented chords.
- Major sounds settled; augmented sounds like it is stretching upward.
Quick test: is it a augmented chord?
Four chords on different roots. Each is a augmented chord or a chord it is often confused with.
Score: / 4 (your score updates as you answer)
Augmented chords on all 12 roots
Spelled by letter from the formula, so thirds are always a letter apart (E♭, not D♯, in C minor).
| Chord | Notes | Hear it |
|---|---|---|
| Caug | C E G♯ | |
| D♭aug | D♭ F A | |
| Daug | D F♯ A♯ | |
| E♭aug | E♭ G B | |
| Eaug | E G♯ B♯ | |
| Faug | F A C♯ | |
| F♯aug | F♯ A♯ C♯# | |
| Gaug | G B D♯ | |
| A♭aug | A♭ C E | |
| Aaug | A C♯ E♯ | |
| B♭aug | B♭ D F♯ | |
| Baug | B D♯ F♯# |
Frequently asked questions
What notes are in an augmented chord?
Root, major third and augmented fifth: 1, 3, sharp 5. C augmented is C E G sharp, F augmented is F A C sharp, G augmented is G B D sharp.
What is the formula of an augmented chord?
0, 4, 8 semitones: two major thirds stacked.
Why are there only four augmented chords?
Each one splits the 12 semitones into three equal parts of 4. Starting on C, E or G sharp gives the same three keys on a piano, so only 12 / 3 = 4 distinct augmented triads exist.
How is an augmented chord written?
Caug or C+. Some charts write C(♯5).