B diminished chord on piano (Bdim)
Bdim is B, D and F. You'll find B just right of the group of three black keys (a white key). Hit Play and watch each key light as it sounds.
root position · B–D–F · right hand 1-3-5
- Notes
- B · D · F
- Formula
- 1 · ♭3 · ♭5
How to play Bdim on piano
Count keys (black and white) from B: 3 half steps up to D then 3 half steps up to F. Those 3 keys are Bdim.
- Right hand: 1 on B, 3 on D and 5 on F.
- Left hand: 5 on B, 3 on D and 1 on F.
- On the keyboard it's white, white and white keys.
Bdim inversions
- root position: B–D–F. RH 1-3-5.
- 1st inversion: D–F–B, with D at the bottom. Right hand 1-2-5.
- 2nd inversion: F–B–D, F lowest. Right hand 1-3-5.
Use the inversions to stay put: the next chord is often one inversion away from where your hand already is, as the changes below show.
Bdim chord changes
The chords Bdim usually goes to, and what changes under your fingers.
- C (leads up a half step): Bdim to C: play C in root position (C–E–G), while B moves up to C, D up to E and F up to G. C on piano
- Cm (leads up a half step): Bdim to Cm: play Cm in root position (C–E♭–G), while B moves up to C, D up to E♭ and F up to G. Cm on piano
- Em (iii in C major): Bdim to Em: play Em in 2nd inversion (B–E–G) and B stays under the same finger, while D moves up to E and F up to G. Em on piano
Bdim is a diminished triad: two minor thirds stacked. Bdim rarely stays long; it's a passing chord that usually climbs a half step to the next chord. On piano you hear it best with the keys pressed together, then rolled.
A short Bdim drill
Roll the chord up and back down, B, D, F, D, B, before playing it as a block. Finish with the inversions in order: B–D–F; D–F–B; F–B–D.
The keys of Bdim
Bdim is a diminished chord, 1–♭3–♭5 from B. Root position, from the bottom: how Bdim is built.
| Note | Key | Fingers | Role |
|---|---|---|---|
| B | white key | RH 1 · LH 5 | root |
| D | white key | RH 3 · LH 3 | minor third |
| F | white key | RH 5 · LH 1 | diminished fifth |
Where Bdim shows up
Bdim on guitar and ukulele
The same notes on another instrument: Bdim on guitar and Bdim on ukulele. This page puts all three side by side.
Next to try on piano
Other diminished chords
Bdim on piano: questions
What notes are in Bdim on piano?
B, D and F: B (white key), D (white key) and F (white key). Right hand 1-3-5, left hand 5-3-1.
How do you play Bdim on piano?
Press B, D and F together, all white keys. Right hand: 1 on B, 3 on D and 5 on F.
What are the inversions of Bdim?
1st inversion (D–F–B) and 2nd inversion (F–B–D), after root position (B–D–F). Same notes, a different one at the bottom.
What does Bdim look like on the keyboard?
white, white and white keys.
Checked automatically: no shape here plays a note outside Bdim. Updated September 2026.