Diminished Guitar Chords

There are a variety of diminished guitar chords. These include, diminished (dim), diminished 5th (-5), diminished 7th (о7 or  dim 7), half diminished 7th (ø7 or m7b5), 7th diminished 5th (7 -5) and 9th diminished 5th (9 -5)

In this session, we will be looking at the diminished triads (3-note chords). Many guitarists play a diminished 7th chord (4-note chord) instead of a diminished chord. The choice is yours, but they are handy to know.

The diminished chord is a dissonant or unstable chord and generally needs resolution. However, if used cleverly, it can create a certain amount of interest in a piece.

Chord Theory

  • A diminished chord is a diminished triad consisting of 2 minor thirds above the root or tonic, therefore having a root, a minor third, and a diminished 5th.
  • The chord formula for a diminished (dim) chord is 1 - ♭3 - ♭5
  • The symbol for a diminished chord is dim, º , or m(♭5)

Example: Calculating C diminished... Cdim,  Cº or  Cm(♭5)

  • Diminished Chords consist of the 1st, ♭3rd, and ♭5th notes of a Major Scale
  • Remember that a minor third is equal to 3 half steps or 3 semitones. If we move a minor third upwards from C, we get E♭ ...(C - C# - D - E♭). If we move another minor 3rd upwards from E♭, we get G♭...E♭- E - F - G♭)
  • 'C' chords, are based on the C major Scale which consists of no sharps or flats.
  • The C scale reads as follows: C - D - E - F - G - A - B - C
  • Chord formula for a diminished chord = 1 - ♭3 - ♭5
  • Substitute the notes of the scale into the formula: 1=C, ♭3=♭E, ♭5=♭G
  • C dim reads as follows: C -♭ E - ♭G
Diminished Chord Table (dim)
dim A A# B♭ B C C# D♭ D D# E♭ E F F# G♭ G G# A♭
Root A A# B♭ B C C# D♭ D D# E♭ E F F# G♭ G G# A♭
♭3rd C C# D♭ D E♭ E F♭(E) F F# G♭ G A♭ A B♭♭(A) B♭ B C♭(B)
♭5th E♭ E F♭(E) F G♭ G A♭♭(G) A♭ A B♭♭(A) B♭ C♭(B) C D♭♭(C) D♭ D E♭♭(D)

Dimimished Chord Charts

Adim - Cdim

Diminished Chords

C#dim / Dbdim - Edim

Diminished  Chords

Fdim - G#dim/ Abdim

Diminished Chords

Take Note:
If you know the basic shape of a diminished chord and know where the root note is located on the guitar fretboard, you can play diminished chords all over the fretboard. This is very handy if you have a favorite shape you like to play. You can play 1 shape and play all 12 keys by just moving up or down the fretboard... very handy!