A DDD cup, or triple D, means your bust measures about 6 inches more than your band. In UK sizing the same cup is called E, and in EU sizing it’s F.
What does DDD mean?
DDD is the sixth cup step: A, B, C, D, DD, then DDD. Each step adds about an inch between bust and band. US brands added a third D rather than move to E, and that’s why US and UK letters stop matching here.
| Cup difference | US label | UK label | EU / French label |
|---|---|---|---|
| 5 in | DD | DD | E |
| 6 in | DDD | E | F |
| 7 in | G (or DDDD) | F | G |
| 8 in | H | FF | H |
Our bra size converter converts any size between systems.
What size comes after DDD?
After DDD, most US brands go to G. A Wacoal America product page we checked, for example, offers cups C, D, DD, DDD, G, H, I and J, with no E or F. Victoria’s Secret and ThirdLove sometimes label the same cup DDDD. In UK sizing it’s F.
So the US alphabet skips E and F. Curvy Kate’s US storefront shows the mapping plainly: “28E (US 28DDD)”, then “28F (US 28G)”. Our G cup guide covers the next step.
DDD vs F
Some US charts write “DDD (F)”. ThirdLove’s chart shows “F (DDD)”. That F is the same 6-inch cup. A UK F is 7 inches, one cup bigger. If you’re a US 34DDD shopping a UK brand, look for 34E, not 34F.
DDD sizes across bands
| US size | UK size | Bust (approx.) | Same cup volume as |
|---|---|---|---|
| 30DDD | 30E | 36 in | 32DD, 34D |
| 32DDD | 32E | 38 in | 34DD, 36D |
| 34DDD | 34E | 40 in | 36DD, 38D |
| 36DDD | 36E | 42 in | 38DD, 40D |
| 38DDD | 38E | 44 in | 40DD, 42D |
Underbust ranges follow the band: just over 32 up to 34 inches for a 34 band, and so on. The sister size calculator lists the full family for any DDD size.
How should a DDD bra fit?
- Band: firm and level. At DDD, a loose band shows up quickly as sore shoulders.
- Cups: fully contain your tissue, including under the arm.
- Wires: wide enough to sit behind your tissue, not on it.
- Center gore: flat against your breastbone.
- Straps: wide or padded, adjusted so they don’t dig.
Our bra fit checker can tell you what a specific problem means.
Where to find DDD bras
Most US brands that go past DD stock DDD. UK brands sell the same size as E, often in more styles, because E sits near the middle of their ranges. If a style comes in “E” and the brand is British, that’s your DDD. Our bras for large breasts guide explains which features help most.
Shopping for DDD cups
Affiliate links-
DDD full coverage bras
Higher cups and side panels for everyday support.
Search Amazon for ddd full coverage bras (opens in a new tab, affiliate link) -
UK E cup balconette bras
The same size in UK labels, often with seamed cups for lift.
Search Amazon for uk e cup balconette bras (opens in a new tab, affiliate link) -
DDD minimizer bras
Reduce projection under shirts while keeping support.
Search Amazon for ddd minimizer bras (opens in a new tab, affiliate link) -
DDD sports bras
Separate cups, hook-and-eye band, adjustable straps.
Search Amazon for ddd sports bras (opens in a new tab, affiliate link)
Results are Amazon’s, not our picks. Check the size range, the return policy and the features above before you buy.
