Diminished Chords (dim, °, half-diminished and dim7)

A diminished chord (written dim or °) has a root, a minor 3rd and a diminished 5th: 1 – ♭3 – ♭5. Add a 7th and you get the half-diminished chord (m7♭5, ø) or the diminished 7th chord (dim7, °7). Below: how the three are built, where they appear in a key, and diagrams on every root.

How they are built

Chord	Symbol	Formula	Example	Where it appears
Diminished triad	dim, °	1 – ♭3 – ♭5	Cdim: C – E♭ – G♭	vii° in major keys, ii° in minor keys
Half-diminished 7th	m7♭5, ø7	1 – ♭3 – ♭5 – ♭7	Cm7♭5: C – E♭ – G♭ – B♭	viiø7 in major keys, iiø7 in minor keys
Diminished 7th	dim7, °7	1 – ♭3 – ♭5 – 𝄫7	Cdim7: C – E♭ – G♭ – B𝄫	vii°7 in minor keys with the raised 7th (harmonic minor)

Why there are only three diminished 7th chords

A diminished 7th chord is four notes, each a minor 3rd (3 semitones) apart, so it splits the octave into four equal steps. Start it on any of its own notes and you get the same four notes again. That leaves only three different diminished 7th chords, each with four names:

C, E♭, F♯ and A
C♯, E, G and B♭
D, F, A♭ and B

On guitar this means one diminished 7th shape moved up 3 frets plays the same chord again.

On every root: names and notes

dim	m7♭5	dim7
Cdim C E♭ G♭	Cm7♭5 C E♭ G♭ B♭	Cdim7 C E♭ G♭ B𝄫
C♯dim C♯ E G	C♯m7♭5 C♯ E G B	C♯dim7 C♯ E G B♭
Ddim D F A♭	Dm7♭5 D F A♭ C	Ddim7 D F A♭ C♭
D♯dim D♯ F♯ A	D♯m7♭5 D♯ F♯ A C♯	D♯dim7 D♯ F♯ A C
Edim E G B♭	Em7♭5 E G B♭ D	Edim7 E G B♭ D♭
Fdim F A♭ C♭	Fm7♭5 F A♭ C♭ E♭	Fdim7 F A♭ C♭ E𝄫
F♯dim F♯ A C	F♯m7♭5 F♯ A C E	F♯dim7 F♯ A C E♭
Gdim G B♭ D♭	Gm7♭5 G B♭ D♭ F	Gdim7 G B♭ D♭ F♭
G♯dim G♯ B D	G♯m7♭5 G♯ B D F♯	G♯dim7 G♯ B D F
Adim A C E♭	Am7♭5 A C E♭ G	Adim7 A C E♭ G♭
A♯dim A♯ C♯ E	B♭m7♭5 B♭ D♭ F♭ A♭	B♭dim7 B♭ D♭ F♭ A𝄫
Bdim B D F	Bm7♭5 B D F A	Bdim7 B D F A♭

Diminished chords on guitar

Cdim

x31x12
C♯dim D♭dim

x42x23
Ddim

xx01x1
D♯dim E♭dim

xx12x2
Edim

xx23x3
Fdim

xx34x4
F♯dim G♭dim

20x21x
Gdim

31x32x
G♯dim A♭dim

42x43x
Adim

x0121x
A♯dim B♭dim

x1232x
Bdim

x20x01

Diminished 7th chords on guitar

Cdim7

xx1212
C♯dim7 D♭dim7

xx2323
Ddim7

xx0101
D♯dim7 E♭dim7

xx1212
Edim7

012020
Fdim7

1x0101
F♯dim7 G♭dim7

2x121x
Gdim7

31x320
G♯dim7 A♭dim7

xx0101
Adim7

x01212
B♭dim7 A♯dim7

x12020
Bdim7

x23131

Diminished chords on piano

Cdim

C E♭ G♭
C♯dim D♭dim

C♯ E G
Ddim

D F A♭
E♭dim D♯dim

E♭ G♭ B𝄫
Edim

E G B♭
Fdim

F A♭ C♭
F♯dim G♭dim

F♯ A C
Gdim

G B♭ D♭
G♯dim A♭dim

G♯ B D
Adim

A C E♭
B♭dim A♯dim

B♭ D♭ F♭
Bdim

B D F

Diminished chords on ukulele

Cdim

5323
C♯dim D♭dim

6434
Ddim

7545
E♭dim D♯dim

2320
Edim

3431
Fdim

4542
F♯dim G♭dim

2020
Gdim

0131
G♯dim A♭dim

1242
Adim

2353
B♭dim A♯dim

3101
Bdim

4212

See also: the guitar chord chart, the piano chord chart, the ukulele chord chart, the chord builder and the chord identifier.

Frequently asked questions

Are diminished chords major or minor?

Neither. Like a minor chord, a diminished chord has a minor 3rd, but its 5th is one semitone lower (a diminished 5th), so it is a chord type of its own: Cdim is C–E♭–G♭, Cm is C–E♭–G.

What is the symbol for a diminished chord?

dim or ° (Cdim = C°). A diminished 7th chord is dim7 or °7, and a half-diminished chord is m7♭5 or ø7. "dim" or "°" alone usually means the three-note chord.

What is a half-diminished chord?

A diminished triad plus a minor 7th: 1 – ♭3 – ♭5 – ♭7, for example Cm7♭5 = C – E♭ – G♭ – B♭. It is the chord on the 7th note of a major key and on the 2nd note of a minor key, when you play 7th chords.

What is the difference between dim and dim7?

Cdim has three notes (C – E♭ – G♭). Cdim7 adds a fourth note a minor 3rd above G♭: C – E♭ – G♭ – B𝄫 (B𝄫 is the same key as A).

Where do diminished chords appear in a key?

In a major key the chord on the 7th note is diminished (B° in C major). In a minor key the chord on the 2nd note is diminished (B° in A minor), and with the raised 7th the chord on the 7th note becomes diminished too (G♯° in A minor).

How do you play a diminished chord on guitar?

Use the charts on this page: each diagram shows where to put each finger. Tap a chord name for every shape of that chord, step-by-step finger placement and its notes.

Last updated: October 12, 2026