What are the sister sizes of 40G?

38H and 42DDD — same cup volume, different band.

Is 40G the same in every brand?

No. A 40G 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.

40G bra size — conversion chart, sister sizes & brands

A 40G bra (US notation) in every regional standard. The same band-and-cup, labelled eight different ways.

US	UK	EU	FR	IT	AU	JP	IN
40G	40F	90G	105G	90G	18F	90G	40F

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 40G

Sister sizes hold the same cup volume with a different band — the quickest fix when a band feels too tight or too loose.

38H 42DDD

Not sure you're a 40G? Two measurements, two minutes — free, nothing stored.

Check my size →

Brands that make G-cup bras

40G FAQ

What is 40G in EU sizing?: 40G (US) is EU 90G. In UK sizing it is 40F. 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 40G?: 38H and 42DDD — same cup volume, different band.
Is 40G the same in every brand?: No. A 40G 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.