C diminished chord on guitar (Cdim)

Cdim is C, E♭ and G♭. The usual shape is x-3-4-5-4-x. Hit Play and watch each string light as it sounds.

x-3-4-5-4-x · movable · medium

Notes: C · E♭ · G♭
Formula: 1 · ♭3 · ♭5
First shape: x-3-4-5-4-x

How to play Cdim on guitar

Shape 1, x-3-4-5-4-x, reading from the low E string on the left, starts at the 3rd fret:

Put your index finger on the A string at the 3rd fret, which is C.
Put your middle finger on the D string at the 4th fret, which is G♭.
Put your ring finger on the B string at the 4th fret, which is E♭.
Put your pinky finger on the G string at the 5th fret, which is C.
Mute the low E and high E strings with the side of a finger so they don't ring.

This shape uses your pinky. It feels weak at first; press with the tip and let the finger stay curved.
Only four strings sound, so strum from the string marked first and aim your pick at the treble strings.

Other ways to play Cdim

x-x-10-8-7-8: movable shape at the 7th fret, medium. A small shape for quick changes and a lighter sound.
x-x-10-11-13-11: movable shape at the 10th fret, medium. Fewer strings, so it sounds lighter and is quicker to change to.
x-15-13-x-13-14: movable shape at the 13th fret, medium. A small shape for quick changes and a lighter sound.

Changing from Cdim to the chords around it

These are the changes you'll meet most often with Cdim, using the first shape of each chord.

C♯ (leads up a half step): Cdim (x-3-4-5-4-x) to C♯ (x-4-6-6-6-4): the index finger lays across the A to high E strings at the 4th fret, move the middle finger to the D string, 6th fret, your ring finger lands on the G string, 6th fret. No finger can stay, so practice lifting all of them together and landing the new shape as a unit. C♯ on guitar
C♯m (leads up a half step): Cdim (x-3-4-5-4-x) to C♯m (x-4-6-6-5-4): the index finger lays across the A to high E strings at the 4th fret, your middle finger lands on the B string, 5th fret, the ring finger goes to the D string, 6th fret. Everything moves: lift the whole hand and place the new shape in one go. C♯m on guitar
Fm (iii in D♭ major): Cdim (x-3-4-5-4-x) to Fm (1-3-3-1-1-1): the index finger lays across the low E to high E strings at the 1st fret, move the middle finger to the A string, 3rd fret, your ring finger lands on the D string, 3rd fret. Everything moves: lift the whole hand and place the new shape in one go. The two chords share C, which is why the change sounds smooth. Fm on guitar

Cdim is a diminished triad: two minor thirds stacked. Cdim rarely stays long; it's a passing chord that usually climbs a half step to the next chord. The slow arpeggio button above makes that quality easy to hear.

Practice Cdim in two minutes

Before strumming, play x-3-4-5-4-x note by note: C then G♭ then C then E♭. A dead note tells you exactly which finger to fix. Next, alternate x-3-4-5-4-x and x-x-10-8-7-8, slowly, until the change takes less than a beat.

Where Cdim shows up

Cdim on piano and ukulele

Cdim on piano and ukulele uses the same 3 notes in a different layout. See all three together.

Related C chords on guitar

Other diminished chords

Cdim on guitar: questions

What notes are in Cdim on guitar?

C, E♭ and G♭. In the x-3-4-5-4-x shape the strings play C (A string), G♭ (D string), C (G string) and E♭ (B string), so C is doubled.

What's the easiest way to play Cdim on guitar?

In standard tuning Cdim can't use open strings. Begin with x-3-4-5-4-x. It uses 4 fingers and no barre, and a capo can make it easier in some songs.

Is Cdim a barre chord on guitar?

Not usually: x-3-4-5-4-x needs no barre.

Which string does Cdim start on?

In the x-3-4-5-4-x shape the lowest string you play is the A string at the 3rd fret, which is C, the root. Skip the low E and high E strings.

Shapes and sound are generated from the notes C, E♭ and G♭ and tested automatically. Updated September 2026.