F cup bra size: a US F and a UK F are not the same size
Two different cups are called F. In the US, several brands print F for the DDD, which is six inches of difference and a UK E. In the UK, F is seven inches and a US G. The letter alone cannot tell you which one a bra is.
US F: 6 in, 15.2 cm of difference
| UK | US | EU | FR | AU | JP (approx.) |
|---|---|---|---|---|---|
| 30E | 30DDD | 65F | 80F | 8E | G65 |
| 32E | 32DDD | 70F | 85F | 10E | G70 |
| 34E | 34DDD | 75F | 90F | 12E | G75 |
| 36E | 36DDD | 80F | 95F | 14E | G80 |
| 38E | 38DDD | 85F | 100F | 16E | G85 |
| 40E | 40DDD | 90F | 105F | 18E | G90 |
UK F: 7 in, 17.8 cm of difference
| UK | US | EU | FR | AU | JP (approx.) |
|---|---|---|---|---|---|
| 34F | 34G | 75G | 90G | 12F | H75 |
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.
F cup size in inches and centimetres
A cup letter is a difference, not a volume. On a 34 band, a US F is a 40 in (101.6 cm) bust and a UK F is a 41 in (104.1 cm) bust. Every row is the band plus the cup's inches, the same arithmetic the calculator uses.
| Band | US F bust | UK F bust |
|---|---|---|
| 30 in | 36 in (91.4 cm) | 37 in (94.0 cm) |
| 32 in | 38 in (96.5 cm) | 39 in (99.1 cm) |
| 34 in | 40 in (101.6 cm) | 41 in (104.1 cm) |
| 36 in | 42 in (106.7 cm) | 43 in (109.2 cm) |
| 38 in | 44 in (111.8 cm) | 45 in (114.3 cm) |
| 40 in | 46 in (116.8 cm) | 47 in (119.4 cm) |
Which F is on the tag
The letter is the same; the size behind it depends on the ladder the brand uses. Each reading, and who prints it.
| Reading | Difference | UK | US | EU | AU |
|---|---|---|---|---|---|
| US F | 6 in (15.2 cm) | 34E | 34DDD | 75F | 12E |
| UK F | 7 in (17.8 cm) | 34F | 34G | 75G | 12F |
- US F. Victoria's Secret prints its cup rows "DD (E)" and "DDD (F)", and ThirdLove says a DDD is the same as an F. Six inches of difference, a UK E.
- UK F. Wacoal, Freya and Elomi pair UK F with US G. Seven inches of difference. SKIMS is excluded because its cup table and measurement grid disagree.
Sister sizes keep the F 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 US F on a 34 band.
| UK | US | Compared with 34E |
|---|---|---|
| 32F | 32G | Tighter band, 1 letter up |
| 34E | 34DDD | This size |
| 36DD | 36DD | 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 US F (6 in) that changes the answer on every band.
| Underbust | Bust | Measured band (UK) | +4 method (US) |
|---|---|---|---|
| 30 in | 36 in | 30E | 34B |
| 34 in | 40 in | 34E | 38B |
| 38 in | 44 in | 38E | 42B |
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.
F 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 | US F (6 in) | UK F (7 in) |
|---|---|---|
| Elomi | Cup within guide range; bands 32 to 48 stated separately; combinations unconfirmed | 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 | Cup within guide range; bands 28 to 44 stated separately; combinations unconfirmed |
| Marks & Spencer | Chart entries: 30 to 46 | Chart entries: 30 to 46 |
| Victoria's Secret | International chart: 30 to 44. US guide: bands 30 to 46, cups A to O; combinations unconfirmed | 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 | 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 F cup
One letter, two sizes an inch apart
Victoria's Secret and ThirdLove use F as another name for DDD (six inches). Wacoal, Freya and Elomi have no US F at all: their US ladders run DD, DDD, G, H, and the UK F sits beside the US G (seven inches). SKIMS's grid runs DD, F, G, H one step at a time, while its cup table pairs F with UK F. Its two charts disagree, so we do not convert a SKIMS F. The US F alias and the UK F described here remain two different cups.
Read the ladder, not the letter
If a chart prints DDD and F as one cup ("DDD (F)", as Victoria's Secret does), they are the same size. On the Wacoal, Freya and Elomi charts, a UK F converts to US G. SKIMS puts F one step after DD in its measurement grid but pairs it with UK F in its cup table. Use SKIMS's grid with your measurements and try the bra on. Our converter reads a US F as the DDD alias; it does not resolve SKIMS's conflicting charts.
Even Marks & Spencer's US column is not steady
Its US size guide lists a UK 32F as a US 32G, which matches Wacoal, and a UK 34F as a US 34DDD, which does not. Two bands of the same chart give two answers.
What the +4 method does to a six-inch F
A 32 in underbust and a 38 in bust measure 32E, the DDD/F size. The +4 method pads the band to 36 and gives 36B: four cup letters down and a band two steps up.
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
- A cupWhat the letter means, by band
- B cupWhat the letter means, by band
- D cupWhat the letter means, by band
- DD cupWhat the letter means, by band
- E 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.
- 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)
- 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)
- ThirdLove, "How To Measure Your Bra Size At Home": DD = E and DDD = F; half-cup sizes; do not round (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)
- Elomi, "International Size Guide": US underband and cup sizing, B to O cups and 32 to 48 bands; UK, EU, FR, AU/NZ, US and JP rows (UK cups to KK, US to P) (opened 29 September 2026)
- SKIMS, "Bra Size Guide": underband/overbust grid and US/UK/EU/AU cup table disagree above DD; grid skips DDD (opened 25 September 2026)
- Marks & Spencer US, "Bras size guide": UK, AU/NZ, US/CA, EU and FR conversion table (opened 25 September 2026)
- Berlei Australia, size charts: AU band = underbust row, cups A to H with no FF or GG
- Wikipedia, "Bra size": UK and US cup ladders, the +4 method, EN 13402 and JIS cup steps