30A bra size: chest and cup measurements, sister sizes in inches and cm, example of celebrity breasts

According to our data, 1,28% of women in the United States, or 1738676 people, have this size. Among them: Hayley Williams, Saoirse Ronan, Jayma Mays. Below you will learn how size 30A differs from sizes 30AA, 32AA, 28A, 32A, 28B, 30B. Find out why it’s smaller than average.

How many inches and centimeters in 30A bra size

	in	cm
Bust measurements (US+0\ UK+0)	30 – 33	76,2 – 83,8
Underbust measurements (US+0\ UK+0)	29 – 31	73,7 – 78,7
Bust (US+4\ UK+4)	26 – 29	66 – 73,7
Underbust (US+4\ UK+4)	25 – 27	63,5 – 68,6

Bra size (US+0\UK +0 system)	Cup diameter	Volume of one cup	Weight of both breasts
30A	8.9 cm (3+1/2 in)	184 cm3 (11 cu in)	0.33 kg (0.7 lb)

Examples of what size 30A breasts look like in celebrities

1. Hayley Williams

Untitled by ronalfy, on Flickr. Attribution 2.0 Generic (CC BY 2.0)

2. Saoirse Ronan

Jayma Mays by Kristin Dos Santos, on Flickr. Attribution-ShareAlike 2.0 Generic (CC BY-SA 2.0)

3. Jayma Mays

142624_9666 by Walt Disney Television, on Flickr. Attribution-NoDerivs 2.0 Generic (CC BY-ND 2.0)

30A VS other sizes

vs 28A: The 28A bra has 2 inches less band. And the cup volume is slightly smaller.
vs 32A: The 32A bra has 2 inches more band. And the cup volume is slightly larger.
vs 30AA: The 30AA bra has the same band size. But the cup volume is smaller.
vs 30B: The 30B bra has the same band size. But the cup volume is larger.
vs 28B: It’s a sister size. The 28B bra has the same cup volume. But the band is a little tighter.
vs 32AA: It’s a sister size. The 32AA bra has the same cup volume. But the band is a little looser.

30A sister size chart

	Sister size down	Current bra size	Sister size up
US/UK	28B	30A	32AA

Is 30A big, small or medium?

Both size 30A breasts weight 0.7 lbs (0.33 kg). The volume of one breast is 11 cubic inches (184 cm3). This is the volume and weight of 3,02% of women in the United States, or 4098307 people.

The number of women with smaller breasts is 1,41%. 30A is conventionally smaller than average size.

11,24% of women in the United States have a A cup size. 3,5% have a smaller cup size. The A cup size is conventionally smaller than the average cup size.

30A equivalents

US+0 system:

EU (Europe) – 75AA
FR/BE/ES – 90AA
AU/NZ – 12AA
JP/KO – 75AA
IT – 3AA
UK+0 – 30A
UK+4 – 34AA
US+4 – 34AA

US+4 system:

EU (Europe) – 65AA
FR/BE/ES – 80AA
AU/NZ – 8AA
JP/KO – 65A
IT – 1AA
UK+0 – 26D
US+0 – 26D
UK+4 – 30A

What size sports bra for 30A

30A (US+0/UK+0 system) = XS

30A (US+4/UK+4 system) = M