F♯ Diminished Chord (F#dim, Gbdim) on Piano
The F#dim chord (F# diminished) is built from 3 notes: F# – A – C. It is also written as Gbdim.
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 F# | Semitones |
|---|---|---|---|
| F# | 1 | root | 0 |
| A | b3 | minor 3rd | 3 |
| C | 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 | F# – A – C | F# in the bass |
| 1st inversion | A – C – F# | A in the bass |
| 2nd inversion | C – F# – A | C 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 F# and applying that formula produces F#, A, C. Learn the formula once and you can build a diminished chord on any of the twelve roots.
Keys that contain F#dim
Every note of F#dim belongs to these keys, so it will sit naturally in a progression written in any of them.
Other chords on F#
Diminished chords on other roots
Frequently asked questions
What notes are in a F#dim chord?
A F#dim chord contains the notes F#, A, C. Those are the 1, b3, b5 degrees measured from the root note F#.
How do you play F#dim on piano?
Place your thumb on F#, then add A and C above it. With a right hand in root position the common fingering is 1–3–5.
Is F#dim the same as Gbdim?
Yes. F#dim and Gbdim are enharmonic equivalents — they sound identical and use the same piano keys. Which spelling you use depends on the key you are playing in.