C♯ Diminished Chord (C#dim, Dbdim) on Piano
The C#dim chord (C# diminished) is built from 3 notes: C# – E – G. It is also written as Dbdim.
Play these notes on a MIDI keyboard, your computer keyboard, or the on-screen keys and ChordKeys will name the chord back to you.
Notes and intervals
| Note | Degree | Interval from C# | Semitones |
|---|---|---|---|
| C# | 1 | root | 0 |
| E | b3 | minor 3rd | 3 |
| G | b5 | diminished 5th | 6 |
Inversions
Rearranging which note sits at the bottom gives you 3 playable voicings of the same chord. Inversions let you move between chords with less hand movement.
| Voicing | Notes | Bass note |
|---|---|---|
| Root position | C# – E – G | C# in the bass |
| 1st inversion | E – G – C# | E in the bass |
| 2nd inversion | G – C# – E | G in the bass |
How the diminished chord is built
Every diminished chord uses the same interval formula: 1 (0 semitones), b3 (3 semitones), b5 (6 semitones). Starting on C# and applying that formula produces C#, E, G. Learn the formula once and you can build a diminished chord on any of the twelve roots.
Keys that contain C#dim
Every note of C#dim belongs to these keys, so it will sit naturally in a progression written in any of them.
Other chords on C#
Diminished chords on other roots
Frequently asked questions
What notes are in a C#dim chord?
A C#dim chord contains the notes C#, E, G. Those are the 1, b3, b5 degrees measured from the root note C#.
How do you play C#dim on piano?
Place your thumb on C#, then add E and G above it. With a right hand in root position the common fingering is 1–3–5.
Is C#dim the same as Dbdim?
Yes. C#dim and Dbdim are enharmonic equivalents — they sound identical and use the same piano keys. Which spelling you use depends on the key you are playing in.