What are the sister sizes of 40DDD?

38G and 42DD — same cup volume, different band.

Is 40DDD the same in every brand?

No. A 40DDD 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.

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

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

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

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 40DDD

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

38G 42DD

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

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Brands that make DDD-cup bras

40DDD FAQ

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