What are the sister sizes of 40D?

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

Is 40D the same in every brand?

No. A 40D 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.

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

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

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

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 40D

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

38DD 42C

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

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Brands that make D-cup bras

40D FAQ

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