C diminished seventh (Cdim7) chord on guitar

The C diminished seventh chord (Cdim7) is a diminished seventh chord (three stacked minor thirds), made of four notes: C – E♭ – G♭ – B𝄫.

Dots show:

Position 1medium

E shape, fret 8hard

D shape, fret 10medium

Position 13medium

Tap a string on a diagram to hear just that string. The sound is generated in your browser with a physical string model.

Chord finder Transposer Tuner

What the Cdim7 chord sounds like

A diminished seventh is three stacked minor thirds, so it is symmetrical: four different roots give the same notes. A dramatic, tense passing chord.

Notes of the Cdim7 chord

Degree	Note	Interval from the root
1	C	root
3	E♭	minor third (3 semitones)
5	G♭	diminished fifth (6 semitones)
7	B𝄫	diminished seventh (9 semitones)

How to play it – with fingering

Position 1, barre at fret 1

String 1 (e): fret 2, ring finger (G♭4)
String 2 (B): fret 1, index finger (C4)
String 3 (G): fret 2, middle finger (B𝄫3)
String 4 (D): fret 1, index finger (E♭3)
String 5 (A): fret 3, little finger (C3)
String 6 (E): not played

For the barre, lay your index finger flat across all the marked strings at fret 1; your other fingers press the higher frets.

E shape, fret 8, barre at fret 8

String 1 (e): fret 8, index finger (C5)
String 2 (B): fret 10, little finger (B𝄫4)
String 3 (G): fret 8, index finger (E♭4)
String 4 (D): fret 10, ring finger (C4)
String 5 (A): fret 9, middle finger (G♭3)
String 6 (E): fret 8, index finger (C3)

For the barre, lay your index finger flat across all the marked strings at fret 8; your other fingers press the higher frets.

D shape, fret 10

String 1 (e): fret 11, little finger (E♭5)
String 2 (B): fret 10, middle finger (B𝄫4)
String 3 (G): fret 11, ring finger (G♭4)
String 4 (D): fret 10, index finger (C4)
String 5 (A): not played
String 6 (E): not played

The “C, A, G, E and D shapes” are the CAGED system: you slide the shape of the open C, A, G, E or D chord up the neck and your index finger (a barre) takes over the job of the nut. That way the same chord can be played in five places, anywhere on the fretboard.

Tuning: E A D G B E (low to high). String 6 is the thickest, the low E. In the diagram, × means the string is not played, and a circle means an open string.

Playing Cdim7 with a capo

A capo clamps all the strings at one fret, so a familiar open shape sounds higher. You can also get a Cdim7 chord with these open shapes:

Capo: fret 3
shape: Adim7

Rework a whole song for a capo: chord transposer →

Similar chords and substitutes

If Cdim7 is too hard, or you want a different colour in the same spot, these chords are worth a try.

Substitutes (by function)

A♭7 – an incomplete dominant: the diminished chord is the top of this seventh chord
C♯ – where it leads (leading tone → root)

Same notes

E♭dim7 – the same notes with a different root
F♯dim7 – the same notes with a different root
Adim7 – the same notes with a different root

Simpler versions

Cdim – all 3 of its notes are in this chord

Frequently asked questions

What notes are in the Cdim7 chord?

C, E♭, G♭, B𝄫. The root is C; the intervals of the other notes from the root: minor third, diminished fifth, diminished seventh.

What is the easiest way to play Cdim7 on guitar?

The easiest shape above is “Position 1”. We show 4 shapes, from open and easy versions to movable barre shapes higher up the neck. With a capo you can also play it as a Adim7 shape at fret 3.

How do I read the chord diagram?

Strings run from the lowest (left) to the highest (right) – tick “Left-handed” to mirror it. Rows are frets; a number at the side shows the starting fret. Dots are fingers (1 index, 2 middle, 3 ring, 4 little), a long bar is a barre, × means don't play that string and ○ means play it open.

How is the Cdim7 chord written?

The chord symbol is Cdim7, and its full name is C diminished seventh.