B diminished chord on ukulele (Bdim)

Bdim is B, D and F. The usual shape is 4-2-1-2. Tap Play, then slow it down.

4-2-1-2 · movable · medium

Notes: B · D · F
Formula: 1 · ♭3 · ♭5
First shape: 4-2-1-2

How to play Bdim on ukulele

Shape 1, 4-2-1-2, reading from the G string on the left:

Put your index finger on the E string at the 1st fret, which is F.
Put your middle finger on the C string at the 2nd fret, which is D.
Put your ring finger on the A string at the 2nd fret, which is B.
Put your pinky finger on the G string at the 4th fret, which is B.

Your little finger has a job in this shape; it gets stronger in a week or two of short daily practice.
A four-fret stretch: drop your wrist a little and point your thumb up the back of the neck.
Strum with the pad of your index finger or thumb, all four strings, across the spot where the neck meets the body.

Other ways to play Bdim

7-5-7-5: movable shape at the 5th fret, medium. A different set of strings gives a different color of the same chord.
10-11-10-8: movable shape at the 8th fret, medium. Higher up the neck it sounds brighter; handy when another guitar is already playing a lower shape.

Moving between Bdim and its neighbours

Songs rarely hold Bdim for long. Here's what your hand does on the moves that come up most.

C (leads up a half step): Bdim (4-2-1-2) to C (0-0-0-3): the index finger goes to the A string, 3rd fret. C on ukulele
Cm (leads up a half step): Bdim (4-2-1-2) to Cm (0-3-3-3): your index finger lands on the C string, 3rd fret, the middle finger goes to the E string, 3rd fret, move the ring finger to the A string, 3rd fret. No finger can stay, so practice lifting all of them together and landing the new shape as a unit. Cm on ukulele
Em (iii in C major): Bdim (4-2-1-2) to Em (0-4-3-2): move the index finger to the A string, 2nd fret, move the middle finger to the E string, 3rd fret, your ring finger lands on the C string, 4th fret. No finger can stay, so practice lifting all of them together and landing the new shape as a unit. B carries over from one chord to the other. Em on ukulele

Bdim is a diminished triad: two minor thirds stacked. All 3 notes of Bdim fit on the ukulele's four strings, with one of them doubled. The slow arpeggio button above makes that quality easy to hear.

Practice Bdim in two minutes

Before strumming, play 4-2-1-2 note by note: B then D then F then B. A dead note tells you exactly which finger to fix. Finish by moving between 4-2-1-2 and 7-5-7-5 to learn two positions of the same chord.

Where Bdim shows up

Bdim on guitar and piano

Switching instruments? Try Bdim on piano or Bdim on guitar, or compare them on the Bdim chord page.

Related B chords on ukulele

Other diminished chords

Bdim on ukulele: questions

What notes are in Bdim on ukulele?

B, D and F. In the 4-2-1-2 shape the strings play B (G string), D (C string), F (E string) and B (A string), so B is doubled.

What's the easiest way to play Bdim on ukulele?

Bdim has no open-string shape in standard tuning, so every version needs a barre or a stretch. Start with 4-2-1-2. It uses 4 fingers and no barre, and a capo is worth trying when the song allows.

Is Bdim a barre chord on ukulele?

Not the usual shape: 4-2-1-2 needs no barre.

Which string does Bdim start on?

In the 4-2-1-2 shape the lowest string you play is the G string at the 4th fret, which is B, the root.

Every shape above plays only B, D and F, checked by the site's tests. Updated September 2026.