DD cup size: the last letter the UK and US share
DD is five inches of difference, one more than D. It is the last letter the UK and US labels share before their ladders split: the next inch is a UK E and a US DDD. EU and French charts already print this cup as E.
UK DD: 5 in, 12.7 cm of difference
| UK | US | EU | FR | AU | JP (approx.) |
|---|---|---|---|---|---|
| 30DD | 30DD | 65E | 80E | 8DD | F65 |
| 32DD | 32DD | 70E | 85E | 10DD | F70 |
| 34DD | 34DD | 75E | 90E | 12DD | F75 |
| 36DD | 36DD | 80E | 95E | 14DD | F80 |
| 38DD | 38DD | 85E | 100E | 16DD | F85 |
| 40DD | 40DD | 90E | 105E | 18DD | F90 |
AU follows Berlei; Wacoal, Freya and Elomi keep UK FF and GG instead. JP is approximate because Japanese cup steps are 2.5 cm rather than one inch; our JP column stops at I. Wacoal's guide continues to JP K. "n/a" means outside this converter, not that the size does not exist. Cup-system definitions.
DD cup size in inches and centimetres
A cup letter is a difference, not a volume. On a 34 band, a UK DD is a 39 in (99.1 cm) bust. Every row is the band plus the cup's inches, the same arithmetic the calculator uses.
| Band | UK DD bust |
|---|---|
| 30 in | 35 in (88.9 cm) |
| 32 in | 37 in (94.0 cm) |
| 34 in | 39 in (99.1 cm) |
| 36 in | 41 in (104.1 cm) |
| 38 in | 43 in (109.2 cm) |
| 40 in | 45 in (114.3 cm) |
Sister sizes keep the DD cup's volume
Go down one band and up one letter, or up one band and down one letter, and the cup volume stays the same. Shown for UK DD on a 34 band.
| UK | US | Compared with 34DD |
|---|---|---|
| 32E | 32DDD | Tighter band, 1 letter up |
| 34DD | 34DD | This size |
| 36D | 36D | Looser band, 1 letter down |
The full diagonal chart, with fit fixes for a band that rides up or digs in, is on the sister sizes page.
What the +4 method does to this cup
Our +4 comparison rounds measurements to whole inches, adds 4 to an even underbust (5 to an odd one) and subtracts the padded band from the bust. Differences below 1 are labelled AA. For UK DD (5 in) that changes the answer on every band.
| Underbust | Bust | Measured band (UK) | +4 method (US) |
|---|---|---|---|
| 30 in | 35 in | 30DD | 34A |
| 34 in | 39 in | 34DD | 38A |
| 38 in | 43 in | 38DD | 42A |
White and Scurr (2012) found the traditional method overestimated band size and underestimated cup size (Ergonomics 55(6)). A size from an older calculator may not be the size on this page.
DD cup bras: which brand charts list one, by band
Some charts print individual sizes; others state band and cup ranges separately. Being inside both ranges does not confirm that the brand makes that combination. None of these checks confirms stock.
| Brand | UK DD (5 in) |
|---|---|
| Elomi | Cup within guide range; bands 32 to 48 stated separately; combinations unconfirmed |
| Freya | Cup within guide range; bands 28 to 44 stated separately; combinations unconfirmed |
| Marks & Spencer | Chart entries: 28 to 46 |
| Victoria's Secret | International chart: 30 to 44. US guide: bands 30 to 46, cups A to O; combinations unconfirmed |
| ThirdLove | Cup within guide range; bands 32 to 44 stated separately; combinations unconfirmed |
Elomi: US underband and cup sizing, 32 to 48 bands and B to O cups (UK B to K; its chart continues to UK KK). Freya: bands 28 to 44, UK cups B to K. Marks & Spencer: its UK row lists sizes from 28AA to 46K (no FF, HH or JJ); matched here by the label as printed. Victoria's Secret: US guide: bands 30 to 46, cups A to O, not every style in every size; international chart: bands 30 to 44, AA to DDD (UK E). The US ranges do not confirm every band/cup combination. ThirdLove: bands 32 to 44, AA to H in US labels, plus half cups; the ranges do not verify every combination or the UK pairing for G/H.
What is particular about the DD cup
"Double D" is not a separate scale
The US ladder writes the steps after D as DD and DDD. The UK and US both write it DD, five inches of difference, and agree on it exactly: it is the last letter both use before the UK goes to E and the US to DDD (Wikipedia, "Bra size").
Some US brands print this size as "E" instead
Victoria's Secret and ThirdLove use E as an alias for DD, and F for DDD. Their E alias is a UK DD; EU and French charts also print E for that five-inch cup. A UK E is one inch larger, six inches of difference and a US DDD. Check the brand's chart before you order.
Is a DD cup big?
Not on its own. A 34DD holds the same cup volume as 32E and 36D, and the same as 38C two bands up. A 30DD and a 40DD share the letter and little else; the band sets the volume.
Marks & Spencer's US column calls it a D
On the M&S US size guide a UK 34DD is a US 34D and a UK 36DD is a US 36D, while a UK 32DD keeps its letters (US 32DD). Wacoal, Freya and Victoria's Secret print UK DD as US DD, and so does this site.
What the +4 method does to a DD
A 34 in underbust and a 39 in bust measure 34DD. The +4 method pads the band to 38 and takes the cup from 39 − 38 = 1 in, so it prints 38A: four cup letters down and two band sizes up. 32/37 gives 36A the same way.
Quick answers
Is DD the same as E?
In EU and French sizes, yes: they print the five-inch cup as E. On a UK tag, no: a UK E is one inch larger, the cup the US calls DDD. Victoria's Secret and ThirdLove also use E as another name for DD.
What is a 34DD in other countries?
UK and US 34DD, EU 75E, France 90E and Australia 12DD. Marks & Spencer's US column prints it as 34D.
What are the sister sizes of 34DD?
UK 32E (US 32DDD) on a band one size tighter and 36D on a band one size looser. All three hold the same cup volume.
Other sizes and tools
- Bra size calculatorMeasure your size with both methods shown
- UK to US converterAny size in any of six systems
- Sister size chartThe full diagonal chart and fit fixes
- 32DDSister sizes, conversions and the measurements that land on 32DD
- 34DDSister sizes, conversions and the measurements that land on 34DD
- 36DDSister sizes, conversions and the measurements that land on 36DD
- A cupWhat the letter means, by band
- B cupWhat the letter means, by band
- D cupWhat the letter means, by band
- E cupWhat the letter means, by band
- F cupWhat the letter means, by band
- G cupWhat the letter means, by band
- H cupWhat the letter means, by band
Sources
Each source was opened and checked on the date shown, or on 25 September 2026. Where sources disagree, the page says so instead of picking one silently.
- Wikipedia, "Bra size": UK and US cup ladders, the +4 method, EN 13402 and JIS cup steps
- White J, Scurr J. Evaluation of professional bra fitting criteria for bra selection and fitting in the UK. Ergonomics 2012;55(6):704-711: 45 women; the traditional method overestimated band and underestimated cup
- Victoria's Secret Customer Care, "Size & Fit: Bras & Bralettes": US guide states bands 30 to 46 and cups A to O, not all styles in all sizes; bralette rows print DD (E) and DDD (F) (opened 25 September 2026)
- ThirdLove, "How To Measure Your Bra Size At Home": DD = E and DDD = F; half-cup sizes; do not round (opened 25 September 2026)
- Marks & Spencer US, "Bras size guide": UK, AU/NZ, US/CA, EU and FR conversion table (opened 25 September 2026)
- Wacoal, "International Size Guide": UK AA to GG paired with US AA to J; AUS/NZ keeps FF and GG; band and cup rows are separate, not a stock list (opened 13 October 2026)
- Freya, "International Bra Size Chart & Bra Sizing": band and cup tables in UK, EU, FR, AU/NZ, US and JP (opened 25 September 2026)
- Berlei Australia, size charts: AU band = underbust row, cups A to H with no FF or GG
- Victoria's Secret Customer Care, "Size & Fit: International Size Chart (Outside the U.S.)": US sizes sold; bands 30 to 44, cups AA to DDD; US DDD = UK E (opened 25 September 2026)