30I bra size — conversion chart, sister sizes & brands
A 30I bra (US notation) in every regional standard. The same band-and-cup, labelled eight different ways.
| US | UK | EU | FR | IT | AU | JP | IN |
|---|---|---|---|---|---|---|---|
| 30I | 30G | 65I | 80I | 65I | 8G | 65I | 30G |
Band conversions are exact; cup fit still varies by brand, style, and body — a conversion is a starting point, not a guarantee.
Sister sizes of 30I
Sister sizes hold the same cup volume with a different band — the quickest fix when a band feels too tight or too loose.
Not sure you're a 30I? Two measurements, two minutes — free, nothing stored.
Check my size →Brands that make I-cup bras
30I FAQ
- What is 30I in EU sizing?
- 30I (US) is EU 65I. In UK sizing it is 30G. Band conversions are exact; cup fit still varies by brand, style, and body — a conversion is a starting point, not a guarantee.
- What are the sister sizes of 30I?
- 28J and 32H — same cup volume, different band.
- Is 30I the same in every brand?
- No. A 30I can fit differently between brands because of pattern, fabric and cup shape. Use it as a starting point and try a sister size when switching brands.