An augmented chord contains a root, major third, and raised fifth. Its formula is 1–3–♯5, so C augmented is C–E–G♯. The raised fifth gives the chord an unsettled sound.
Build any augmented chord by taking a major chord and raising its fifth by one semitone. The change creates a symmetrical structure with unusual inversions and chromatic movement.
What Is the Augmented Chord Formula?
The augmented chord formula is 1–3–♯5. These scale degrees represent the root, major third, and augmented fifth. In semitones measured upward from the root, the positions are 0–4–8.
For C augmented:
- C is the root, or 1
- E is the major third, or 3
- G♯ is the augmented fifth, or ♯5
The result is C–E–G♯. Compare that with C major, C–E–G: only the fifth changes. A broader guide to the major triad formula helps clarify why raising G to G♯ changes the chord quality without changing its third.
The word augmented means enlarged. A perfect fifth spans seven semitones, while an augmented fifth spans eight. The symbol may appear as aug or +, so Caug and C+ normally name the same three-note chord.
How Do You Build an Augmented Chord?
Build an augmented chord by choosing a root, finding its major third and perfect fifth, then raising the fifth by one semitone. You can also stack two major thirds: four semitones from the root to the third and another four from the third to the raised fifth.
Raise the fifth of a major triad
Start with a correctly spelled major chord:
- Write the root, third, and fifth using the formula 1–3–5.
- Keep the root and major third unchanged.
- Raise the fifth by one semitone.
- Preserve the fifth’s letter name when spelling the altered note.
G major is G–B–D. Raising D to D♯ produces Gaug: G–B–D♯. D major is D–F♯–A; raising A to A♯ produces Daug: D–F♯–A♯. This alteration-based method connects naturally with the broader process of constructing guitar chords from intervals.
Calculate the notes from scale degrees
The formula works even when the root includes a flat. E♭ major is E♭–G–B♭. Its fifth, B♭, rises one semitone to B natural, giving E♭aug: E♭–G–B.
A augmented provides another straightforward example. A major is A–C♯–E; raise E to E♯ to get A–C♯–E♯. E♯ sounds like F on an equal-tempered instrument, but E♯ is the correct written fifth because an A-root triad must use some form of A, C, and E. Understanding how chords are assembled in thirds makes these spellings easier to predict.
What Notes Are in Every Augmented Chord?
The following chart applies 1–3–♯5 to all 12 chromatic roots. Some enharmonic root names are omitted to keep the reference practical, but equivalent chords may be named differently according to the key and harmonic context.
| Chord | Formula | Correctly spelled notes |
|---|---|---|
| Caug | 1–3–♯5 | C–E–G♯ |
| C♯aug | 1–3–♯5 | C♯–E♯–G𝄪 |
| Daug | 1–3–♯5 | D–F♯–A♯ |
| E♭aug | 1–3–♯5 | E♭–G–B |
| Eaug | 1–3–♯5 | E–G♯–B♯ |
| Faug | 1–3–♯5 | F–A–C♯ |
| F♯aug | 1–3–♯5 | F♯–A♯–C𝄪 |
| Gaug | 1–3–♯5 | G–B–D♯ |
| A♭aug | 1–3–♯5 | A♭–C–E |
| Aaug | 1–3–♯5 | A–C♯–E♯ |
| B♭aug | 1–3–♯5 | B♭–D–F♯ |
| Baug | 1–3–♯5 | B–D♯–F𝄪 |
A double sharp raises a note by two semitones from its natural form. For example, G𝄪 is enharmonically equivalent to A, but writing A in C♯aug would make the chord look as if it had a sixth instead of a fifth. Correct spelling shows each tone’s harmonic job, not merely the piano key or guitar fret being played.
This distinction is especially useful when interpreting common guitar chord symbols and alterations, where C+, Caug, and C(♯5) may appear in different notational settings.
How Does an Augmented Chord Compare With Other Triads?
An augmented triad differs from a major triad by its raised fifth, from a minor triad by both its third and fifth, and from a diminished triad by both altered intervals. All four basic triad qualities can be compared through their scale-degree formulas.
| Triad quality | Formula | C-root notes | Semitone pattern between chord tones |
| Major | 1–3–5 | C–E–G | 4 + 3 |
| Minor | 1–♭3–5 | C–E♭–G | 3 + 4 |
| Diminished | 1–♭3–♭5 | C–E♭–G♭ | 3 + 3 |
| Augmented | 1–3–♯5 | C–E–G♯ | 4 + 4 |
The major third gives an augmented chord part of its bright major quality, but the raised fifth adds instability. A diminished chord uses two stacked minor thirds, whereas an augmented chord uses two stacked major thirds. The four principal types of triads therefore form a compact map of how changing the third or fifth changes a chord’s identity.
A plain augmented chord should not be confused with C7♯5. Caug has C–E–G♯, while C7♯5 adds the minor seventh B♭. Likewise, Caug(maj7), sometimes written Cmaj7♯5, contains C–E–G♯–B. The extra seventh changes the chord’s color and possible function.
Why Are Augmented Chords Symmetrical?
Augmented triads are symmetrical because both adjacent chord tones are four semitones apart. The final interval from the highest chord tone back to the root’s octave is also four semitones, dividing the 12-semitone octave into three equal parts.
One pitch collection can have three names
Caug contains C–E–G♯. Put E in the bass and the pitches become E–G♯–C, which sound enharmonically like E–G♯–B♯: Eaug. Put G♯ in the bass and the same sounding collection can function as G♯aug, spelled G♯–B♯–D𝄪.
The sounding pitches overlap, but the names are not automatically interchangeable. The bass line, key, melody, and resolution determine the most meaningful root. A deeper explanation of augmented triad structure and inversions separates pitch equivalence from harmonic function.
Why only four unique pitch collections exist
Transposing an augmented triad upward by four semitones reproduces the same three pitch classes in a new order. Consequently, the chromatic octave contains only four distinct augmented pitch-class collections before the pattern repeats.
That symmetry makes the chord harmonically ambiguous. Each note can sound like a possible root, so nearby melody and bass motion often provide more information than the voicing alone.
How Are Augmented Chords Used in Music?
Augmented chords commonly create chromatic voice leading, connect stable chords, or intensify a dominant sound. Their raised fifth tends to move by semitone, giving the ear a clear line even when the chord itself feels ambiguous.
Consider C–Caug–Am:
| Chord | Notes | Moving voice |
| C | C–E–G | G |
| Caug | C–E–G♯ | G♯ |
| Am | A–C–E | A |
The upper voice climbs G–G♯–A while C and E remain common tones through the first two chords. This economical movement explains why an augmented chord can work as a passing harmony rather than behaving like a conventional dominant chord.
Another possibility is C–Caug–F, where G rises to G♯ and then A inside F major. An augmented dominant can also press toward a resolution: G7♯5 contains G–B–D♯–F and may resolve toward C, with D♯ moving to E. For additional context on tension, notation, and musical application, see the guide to how augmented harmony works.
On guitar, a voicing may repeat a chord tone or omit a doubled note; on piano, the three notes can be spread across octaves. Neither choice changes the formula as long as the functional root, major third, and augmented fifth remain represented.
Frequently Asked Questions
What notes are in a C augmented chord?
C augmented contains C, E, and G♯. Its formula is 1–3–♯5, so it is formed by raising the G in C major to G♯.
Is an augmented chord major or minor?
An augmented chord is neither a standard major nor minor triad, although it contains a major third. Its raised fifth gives it a separate quality represented by aug or +.
Are Caug, Eaug, and G♯aug the same chord?
They can use the same sounding pitch classes in equal temperament, but their theoretical spellings and harmonic roots differ. The bass, key, and resolution determine which name best describes the chord’s function.
Why are there only four distinct augmented triad pitch collections?
Each augmented triad divides the octave into three equal four-semitone intervals. Transposing the chord by four semitones only rearranges the same pitch classes, so the pattern produces four unique collections before repeating.
What is the difference between Caug and C7♯5?
Caug is the three-note chord C–E–G♯. C7♯5 contains those notes plus B♭, the minor seventh, which gives it a stronger dominant function.
How do augmented chords usually resolve?
An augmented chord often resolves through semitone motion from its raised fifth to a nearby chord tone. For example, Caug can move to Am as G♯ rises to A, or to F major as G♯ rises to A.
Liam Turner is a guitar theory writer and chord analysis specialist at Chord Calculator. He focuses on chord construction, music theory, scale relationships, harmony tools, and guitar learning resources for musicians, producers, songwriters, and beginners. Liam creates practical, easy-to-follow content around chord progressions, interval formulas, key analysis, and interactive music tools to help users better understand harmony, songwriting, and instrument practice.