C diminished chord on guitar (Cdim)

Also called or written Cdim or

C diminished is built from C, E♭, and G♭. The 3rd fret shape sits in the middle of the neck and requires muting both E strings.

3frCG♭CE♭EADGBE
Positions on the neck1 of 5
Practice C diminished chord

How it is built

CRootE♭Minor thirdG♭Diminished fifth

Formula 1, ♭3, ♭5

Inversions

How do you play a C diminished chord on guitar?

C diminished is played at the 3rd fret as × 3 4 5 4 ×: index finger on the A string at fret 3, middle finger on the D string at fret 4, pinky finger on the G string at fret 5 and ring finger on the B string at fret 4. The low E and high e strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)muted
5 (A)31C (1)
4 (D)42G♭ (♭5)
3 (G)54C (1)
2 (B)43E♭ (♭3)
1 (e)muted

IntermediateThe 3rd fret shape demands a four-fret stretch and precise muting of both E strings, making it intermediate.

8th fret

C diminished is played at the 8th fret as 8 9 10 8 × ×: index finger on the low E string at fret 8, ring finger on the A string at fret 9, pinky finger on the D string at fret 10 and middle finger on the G string at fret 8. The B and high e strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)81C (1)
5 (A)93G♭ (♭5)
4 (D)104C (1)
3 (G)82E♭ (♭3)
2 (B)muted
1 (e)muted

Cdim/E♭ inversion · fret 4

C diminished is played at the 4th fret as × 6 4 5 4 ×: pinky finger on the A string at fret 6, index finger on the D string at fret 4, ring finger on the G string at fret 5 and middle finger on the B string at fret 4. The low E and high e strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)muted
5 (A)64E♭ (♭3)
4 (D)41G♭ (♭5)
3 (G)53C (1)
2 (B)42E♭ (♭3)
1 (e)muted

Cdim/E♭ inversion · fret 9

C diminished is played at the 9th fret as 11 9 10 11 × ×: ring finger on the low E string at fret 11, index finger on the A string at fret 9, middle finger on the D string at fret 10 and pinky finger on the G string at fret 11. The B and high e strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)113E♭ (♭3)
5 (A)91G♭ (♭5)
4 (D)102C (1)
3 (G)114G♭ (♭5)
2 (B)muted
1 (e)muted

Cdim/E♭ inversion · fret 11

C diminished is played at the 11th fret as × × 13 11 13 11: ring finger on the D string at fret 13, index finger on the G string at fret 11, pinky finger on the B string at fret 13 and middle finger on the high e string at fret 11. The low E and A strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)muted
5 (A)muted
4 (D)133E♭ (♭3)
3 (G)111G♭ (♭5)
2 (B)134C (1)
1 (e)112E♭ (♭3)

Why it sounds like that

C diminished uses the formula 1, ♭3, ♭5, producing C, E♭, and G♭. The flattened fifth gives the chord its tense, unstable quality. Contrast it with C minor, which has a perfect fifth.

What goes wrong with C diminished?

  • Letting the low E string ring out, adding an E that is not part of C diminished.
  • Flattening the pinky on the G string, causing the 5th fret note to buzz.
  • Strumming the high E string, which introduces an outside note.

When to use it

C diminished functions as the vii° chord in D♭ major, leading to D♭ major. It also works as a passing chord between C minor and D♭ major. Use it in jazz or classical for a tense, dark color.

Changing to and from C diminished

  • Slide the 3rd fret shape up one fret to the 4th fret to get C♯ diminished.
  • Move to C minor by lifting the pinky from the G string's 5th fret and playing the 5th fret on the B string instead.

Which voicing to use

The 3rd fret shape is the most common and keeps the root C in the bass. The 8th fret shape repeats the voicing higher. The Cdim/E♭ inversions place E♭ in the bass, creating a more ambiguous sound.

Other C chords

Common questions

What is the difference between C diminished and C minor?

C diminished has a flattened fifth (G♭), while C minor has a perfect fifth (G). The diminished fifth creates a more dissonant, tense sound.

Can I play C diminished as a barre chord?

The 3rd fret shape uses no barre, but the 8th fret shape is movable. Slide the 8th fret shape down two frets to get B♭ diminished.

Why are both E strings muted in the 3rd fret shape?

The open E strings are not chord tones of C diminished. Muting them keeps the voicing clean and prevents an unwanted major second clash.

How is C diminished written?

C diminished is written as C° or Cdim. The root is C, and the symbols are C° and Cdim.