BraSizeConversion

34A Bra Size, Fully Explained

7 sizing systems25+ country calculatorsBands 28-60, cups AA-PZero data stored

34A is squarely in the core of the size chart: a mid-range band with a gentle difference. Nearly every brand cuts it, which makes fit problems here almost always construction or wear-routine issues rather than availability ones.

34A in every sizing system

USUKEUFRAUJPKR
34A34A75A90A12AB75B75

Sister sizes of 34A

30C32B34A36AA

Each sister holds roughly the volume of 34A on a different band. Band riding up in a 34A? Try 30C. Band digging painfully? The other direction.

How 34A compares, visually

034A34B

Circle areas scale with estimated cup volume: 34A46 cc per cup, roughly 0.0 kg of tissue per side at typical density. Model documented on the weight page.

Is 34A big?

Is 34A big? In absolute terms it is on the smaller side of the chart, but the honest answer is that the question is mostly noise: the letter only means something relative to the 34 band, and bodies wear the same volume completely differently. What matters is that 34A fits its wearer, which the fit checks decide better than comparison ever will.

Shopping notes for 34A

Confirm the size first: two minutes with the calculator beats inheriting a label. Then let the brand decoder translate 34A into each brand's cut, since the same tag runs shallow at mall brands and deep at UK houses. If 34A passes the band checks but the cup misbehaves, that is usually shape, not size.

Frequently asked questions

What is 34A in UK and European sizing?
34A (US) converts to UK 34A, EU 75A, FR 90A, AU 12A and JP/KR B75. Cup letters diverge after D, which is why the letters differ between systems.
What are the sister sizes of 34A?
30C, 32B, 36AA. Each holds approximately the same cup volume as 34A on a different band: band down pairs with letter up, and vice versa.
Is 34A big?
What matters is that 34A fits its wearer, which the fit checks decide better than comparison ever will..
How much do 34A breasts weigh?
Roughly 0.0 kg (0.1 lb) per breast as an estimate from cup volume at typical tissue density. Real weight varies with tissue composition; see our breast weight page for the method.
Nearby sizes

Last updated August 2026.