F diminished chord (Fdim)
Fdim is F, A♭ and C♭: 1–♭3–♭5 built on F. See and hear it on all three instruments below.
On guitar
x-x-3-1-0-1 · open · easy
- Notes
- F · A♭ · C♭
- Formula
- 1 · ♭3 · ♭5
- First shape
- x-x-3-1-0-1
Fdim on guitar: every shape, finger by finger
On piano
root position · F–A♭–C♭ · right hand 1-3-5
- Notes
- F · A♭ · C♭
- Formula
- 1 · ♭3 · ♭5
Fdim on piano: fingering and inversions
On ukulele
4-5-4-2 · movable · medium
- Notes
- F · A♭ · C♭
- Formula
- 1 · ♭3 · ♭5
- First shape
- 4-5-4-2
Fdim and the chords around it
Here's what the hand does on the most common changes, on guitar and on piano.
- Fdim → F♯ (leads up a half step)
Guitar: Fdim (x-x-3-1-0-1) to F♯ (2-4-4-3-2-2): the index finger lays across the low E to high E strings at the 2nd fret, move the middle finger to the G string, 3rd fret, your ring finger lands on the A string, 4th fret, the pinky finger comes down on the D string, 4th fret. Nothing carries over, so drill it slowly, lifting and landing all fingers at once.
Piano: Fdim to F♯: play F♯ in root position (F♯–A♯–C♯), while F moves up to F♯, A♭ up to A♯ and C♭ up to C♯. F♯ - Fdim → F♯m (leads up a half step)
Guitar: Fdim (x-x-3-1-0-1) to F♯m (2-4-4-2-2-2): the index finger lays across the low E to high E strings at the 2nd fret, your middle finger lands on the A string, 4th fret, the ring finger goes to the D string, 4th fret. No finger can stay, so practice lifting all of them together and landing the new shape as a unit.
Piano: Fdim to F♯m: play F♯m in root position (F♯–A–C♯), while F moves up to F♯, A♭ up to A and C♭ up to C♯. F♯m - Fdim → B♭m (iii in F♯ major)
Guitar: Fdim (x-x-3-1-0-1) to B♭m (x-1-3-3-2-1): your ring finger stays put, the index finger lays across the A to high E strings at the 1st fret, move the middle finger to the B string, 2nd fret, the pinky finger comes down on the G string, 3rd fret. Listen for F, which stays put while the rest moves.
Piano: Fdim to B♭m: play B♭m in 2nd inversion (F–B♭–D♭) and F stays under the same finger, while A♭ moves up to B♭ and C♭ up to D♭. B♭m
How Fdim is built
Fdim is a diminished triad: two minor thirds stacked. It sounds tense and unstable and rarely stays long. Its most common job is to lead up a half step, so Fdim usually moves to F♯ or F♯m.
Count keys (black and white) from F: 3 half steps up to A♭ then 3 half steps up to C♭.
| Note | Role | Half steps | Hear it |
|---|---|---|---|
| F | root | 0 | |
| A♭ | minor third | 3 | |
| C♭ | diminished fifth | 6 |
Keys and progressions with Fdim
You'll find Fdim as vii° in F♯ major. On the minor side it's ii° in E♭ minor.
Chords close to Fdim
- Fdim and Fm differ by one note: C♭ in Fdim, C in Fm. They share F and A♭. Fm
Chords that share most of their notes with Fdim: C♯7, Ddim7, Fdim7, Fm7♭5, G♯m6, G♯dim7.
Every F chord
F diminished chord: questions
What notes are in the F diminished chord?
F, A♭ and C♭. Fdim is built 1–♭3–♭5 from F: A♭ is the minor third and C♭ is the diminished fifth.
How do you play Fdim on guitar?
The usual shape is x-x-3-1-0-1 (open). All 3 guitar shapes.
How do you play Fdim on piano?
Play F, A♭ and C♭ with right-hand fingers 1-3-5. F sits just left of the group of three black keys. Inversions and left hand.
How do you play Fdim on ukulele?
4-5-4-2 in standard GCEA tuning. More ukulele shapes.
What key is Fdim in?
You'll find Fdim as vii° in F♯ major. On the minor side it's ii° in E♭ minor.
What's the difference between Fdim and Fm?
Fdim and Fm differ by one note: C♭ in Fdim, C in Fm. They share F and A♭.
Diagrams and sound come from the same data, tested so they match. Updated September 2026.