D cup measurements by band
The first table shows the measurements each D-cup size is designed around, and the sizes that hold the same volume on neighbouring bands. The second shows how a D is labelled abroad.
| Size | Underbust | Bust | Same volume as |
|---|---|---|---|
| 28D | 28 in (71 cm) | 32 in (81 cm) | 26DD and 30C |
| 30D | 30 in (76 cm) | 34 in (86 cm) | 28DD and 32C |
| 32D | 32 in (81 cm) | 36 in (91 cm) | 30DD and 34C |
| 34D | 34 in (86 cm) | 38 in (97 cm) | 32DD and 36C |
| 36D | 36 in (91 cm) | 40 in (102 cm) | 34DD and 38C |
| 38D | 38 in (97 cm) | 42 in (107 cm) | 36DD and 40C |
| 40D | 40 in (102 cm) | 44 in (112 cm) | 38DD and 42C |
| UK | US | EU / France | Australia |
|---|---|---|---|
| D | D | D | D |
Why a 30D and a 38D look nothing alike
Both are four inches bigger in the bust than the band, so both are called D. The 38D has to wrap around a ribcage eight inches larger, and its cup is scaled up to match. Going by the sister sizes, a 30D holds the same volume as a 34B, and a 38D the same as a 34E. That is four cup sizes apart in real volume, under one letter.
The popular picture of "a D cup" is therefore not one size. It is seven or eight quite different ones.
Are you really a D?
D is the size where mismeasurement shows up most. Size guides that add four or five inches to the underbust give a band that is too big, and a cup letter that is too small to match. Plenty of people wearing a 36C or 36D measure as a 32DD or 32E once the band is taken from their real underbust.
Signs your D may be too small:
- the band rides up at the back,
- the centre panel does not sit flat against your chest,
- you have a slight bulge over the cup edge after you scoop and swoop.
Two measurements with the calculator will tell you where you actually sit.
Bra styles for a D cup
D is in the middle of most ranges, so you can wear almost any style. What suits best depends on your band and shape more than on the letter.
- Smaller bands (28 to 32). The volume is modest. Plunge, balconette, bralettes with cup sizing and lightly lined T-shirt bras all work, and non-wired styles give enough support for most people.
- Middle bands (34 to 36). Most styles suit. A balconette gives lift and a rounded shape. A moulded T-shirt bra gives a smooth line.
- Larger bands (38 and up). There is more weight to carry, so features that add support start to matter: a wider band with three hooks, wider straps and side support panels.
If moulded cups gape on you at the top, that is usually about shape and not size. See why your bra cups are gaping.
Where D cups are sold
Virtually every UK retailer that sells bras stocks D cups in bands from 32 to 38. Availability thins at the ends. A 28D or 30D is mostly found at specialist retailers and online, and D cups in 42 bands and above are carried by fewer shops. Check the size range on the individual product.
One size up, one size down
The cup below D is C. The cup above is DD, and after that comes E. If you are unsure where D sits among the double letters, see UK cup sizes in order.
Frequently asked questions
Is a D cup big?
Not in itself. A D means a four-inch difference between bust and band. On a small band such as a 30 that is a small bust. On a 40 band it is a much larger one. D is the fifth of seventeen UK cup sizes.
What is the difference between a C and a D cup?
One inch of bust measurement on the same band. A 34C is built for a 37-inch bust and a 34D for a 38-inch bust.
Is a D cup the same in the UK and the US?
Yes. D is labelled the same in UK, US, European and Australian sizing. The systems only start to differ at the cup above it.
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