Cherry SizeCalculator › All bra sizes, size by size › 30A
30A bra size — conversions, sister sizes & fit
A 30A fits an underbust of about 63–67 cm with a bust 9–11 cm larger than the band. Here is everything that label actually means — and how to check it really fits you.
Your bra size
30A US
Which measurements give 30A?
| cm | |
|---|---|
| Underbust (snug) | 63–67 |
| Bust (fullest point) | 72–78 |
| Difference (cup volume) | 9–11 |
Between two sizes? Measurements near the edges of these ranges can also fit the neighbouring size — check the sister sizes below and, in doubt, trust the fit checks from our measuring guide.
Sister sizes of 30A
28B and 32AA hold the same cup volume as 30A with a tighter or looser band. If the band of a 30A rides up, try 28B; if it digs in, try 32AA.
Small bands with small cups are genuinely underserved on the high street: many mainstream brands start at a 65 or even 70 band, so a lot of what fits you sits in petite-focused or Asian-market lines. Avoid the classic trap of taking a bigger band to find a cup that exists — a loose band gives no support. Look for brands whose range is confirmed to start at your band, and use the sister size only as a fitting-room fallback.
Who makes 30A? 215 of the 632 brands in the Cherry Size catalogue are confirmed to carry 30A in their standard range. But each of them cuts it differently — the app tells you the exact size to try at every one of them, from your own measurements.
See 30A brand by brand30A in questions
What is 30A in European sizing?
A 30A corresponds to 65A in European sizing and 80A in French/Spanish sizing. The cup volume is identical — only the band numbering changes between systems.
Is 30A big or small?
It is one of the smaller sizes: a petite band with a shallow cup. Cup letters mean nothing alone: a cup only has a volume relative to its band, which is why 28B and 32AA hold exactly the same volume as 30A.
My 30A doesn't fit — what should I try?
If the band rides up or feels loose, go to 28B. If the band digs in while the cup is fine, go to 32AA. If the cup overflows, try one cup up in the same band; if it wrinkles empty, one cup down. Two minutes with the calculator confirms it.
Nearby sizes
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