knowhersize

Reviewed

30D bra size

A 30D has a 30-inch band and a D cup, about 4 inches between band and bust. In the UK it is 30D, in Australia 8D and in Europe 65D.

US
30D
UK
30D
AU
8D
EU
65D
FR
80D

Also fits (sister sizes): 28DD firmer band · 32C looser band · all same-volume sizes ↓

30D measurements

Snug underbust
30–31 in · 76–79 cm
Bust, fullest part
about 34 in · 85–88 cm
Cup difference
4 in (D cup)

These are starting points from the band-and-cup method. Brands differ by about a size, so a two-minute measurement beats any chart.

30D sister sizes

Same cup volume, different band. If a 30D band feels too loose, go down a band and up a cup; if it feels tight, go up a band and down a cup.

30D = UK 30D · AU 8D · EU 65D · FR 80D. Sister sizes: 28DD, 32C. 30D in full →
A
B
C
D
DD
DDD
G
H
28
30
32
34
36
38
40
42
44
28DD30D32C34B36A38AA

If a 30D doesn't fit

Band rides up at the back
Try 28DD
Band digs in, cups fit
Try 32C
Spilling over the cups
Try 30DD
Cups gape or wrinkle
Try 30C

Not sure what's wrong? Run through the 4-point fit check.

30D questions

What is the sister size of 30D?

28DD (one band down, one cup up) and 32C (one band up, one cup down). Sister sizes hold the same cup volume on a different band.

What is 30D in UK, Australian and European sizes?

UK 30D, Australia 8D, Europe 65D and France 80D. US and UK cup letters match up to DD and then split.

What measurements are a 30D?

A snug underbust of about 30–31 in (76–79 cm) and a bust of about 34 in (85–88 cm). Measure with the tape level and use the calculator for an exact result.

Is 30D a big size?

30D has a mid-range cup volume for a 30 band. Cup letters only mean something next to the band: a 30D holds the same as 28DD or 32C.