Cherry SizeCalculator › All bra sizes, size by size › 40DDD
40DDD bra size — conversions, sister sizes & fit
A 40DDD fits an underbust of about 88–92 cm with a bust 21–24 cm larger than the band. Here is everything that label actually means — and how to check it really fits you.
Your bra size
40DDD US
Which measurements give 40DDD?
| cm | |
|---|---|
| Underbust (snug) | 88–92 |
| Bust (fullest point) | 109–116 |
| Difference (cup volume) | 21–24 |
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 40DDD
38DDDD and 42DD hold the same cup volume as 40DDD with a tighter or looser band. If the band of a 40DDD rides up, try 38DDDD; if it digs in, try 42DD.
Deep cups on standard bands are well covered by full-bust specialists and increasingly by mainstream brands' extended ranges — but cut quality varies enormously. Prioritise firm bands (the band does 80% of the work, and that matters more with more weight to support), side support panels that keep tissue forward, and top edges that don't cut in. If straps dig, the band is almost always the real culprit.
Who makes 40DDD? 234 of the 632 brands in the Cherry Size catalogue are confirmed to carry 40DDD 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 40DDD brand by brand40DDD in questions
What is 40DDD in European sizing?
A 40DDD corresponds to 90F in European sizing and 105F in French/Spanish sizing. The cup volume is identical — only the band numbering changes between systems.
Is 40DDD big or small?
It is a full-bust size: a deep cup on a standard band, well served by specialist lines. Cup letters mean nothing alone: a cup only has a volume relative to its band, which is why 38DDDD and 42DD hold exactly the same volume as 40DDD.
My 40DDD doesn't fit — what should I try?
If the band rides up or feels loose, go to 38DDDD. If the band digs in while the cup is fine, go to 42DD. 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
Your size, everywhere you shop
Cherry Size keeps your measurements on your iPhone, translates them into 632 brands, tracks changes through pregnancy, nursing or weight shifts — and never uploads a thing.
Download on the App Store