The UK to US bra size converter
Convert your size
Pick your UK band and cup — the band number usually carries straight across, so we focus on getting the cup letter right.
The band number usually stays put. It's the cup letters that drift apart — and by the time you reach G and H, the two systems barely agree. Here's the full conversion chart, plus the reasoning behind it.
Buying a bra from a US brand when you normally wear a UK size can be confusing. The number may look familiar, but the cup letters can change. For example, a UK 32F is not usually sold as a US 32F — the closest US label is commonly around 32G.
A UK to US bra size converter helps you understand these differences before ordering a bra online. The important point is that the band number usually stays the same, while the cup lettering changes, especially after a D or DD cup.
This guide explains how UK and US bra sizes compare, how to convert your size, why different charts sometimes show different answers, and how to check the final fit.
UK to US bra size conversion chart
UK and US band numbers are generally the same — find your UK size on the left and read across for the approximate US equivalent.
| UK Bra Size | Approx. US Bra Size |
|---|---|
| 28A | 28A |
| 28B | 28B |
| 28C | 28C |
| 28D | 28D |
| 28DD | 28DD |
| 28E | 28DDD/F |
| 28F | 28G |
| 28FF | 28H |
| 28G | 28I |
| 28GG | 28J |
| 28H | 28K |
| 30A | 30A |
| 30B | 30B |
| 30C | 30C |
| 30D | 30D |
| 30DD | 30DD |
| 30E | 30DDD/F |
| 30F | 30G |
| 30FF | 30H |
| 30G | 30I |
| 30GG | 30J |
| 30H | 30K |
| 32A | 32A |
| 32B | 32B |
| 32C | 32C |
| 32D | 32D |
| 32DD | 32DD |
| 32E | 32DDD/F |
| 32F | 32G |
| 32FF | 32H |
| 32G | 32I |
| 32GG | 32J |
| 32H | 32K |
| 34A | 34A |
| 34B | 34B |
| 34C | 34C |
| 34D | 34D |
| 34DD | 34DD |
| 34E | 34DDD/F |
| 34F | 34G |
| 34FF | 34H |
| 34G | 34I |
| 34GG | 34J |
| 34H | 34K |
| 36D | 36D |
| 36DD | 36DD |
| 36E | 36DDD/F |
| 36F | 36G |
| 36FF | 36H |
| 36G | 36I |
| 36GG | 36J |
| 36H | 36K |
This is a starting conversion guide, not a guarantee that every brand will use exactly the same label. UK and US sizing systems begin similarly but become different as the cup size increases — always check the specific brand's own size chart before ordering.
How does UK to US bra size conversion work?
A bra size has two main parts: the band size and the cup size. The number — 32, 34, 36 and so on — represents the band around the ribcage. The letter represents the cup volume in relation to the band. For most UK and US bras, the band number stays the same during a basic conversion.
For example: UK 32F → approximately US 32G. The number 32 remains 32. The cup letter changes from F to G.
The difference becomes more noticeable after D, because the two systems use different cup-letter sequences. UK brands commonly use:
D → DD → E → F → FF → G → GG → H → HH → J
Many US brands instead use:
D → DD → DDD → G → H → I → J → K
This is the main reason a UK cup letter cannot simply be matched to the same US letter.
Why a UK F is not usually a US F
This is one of the most common mistakes when converting bra sizes. A UK F and US F do not normally represent the same point in the cup progression — if you wear a UK 34F, you may need approximately a US 34G rather than a US 34F.
These are approximate label conversions. The actual fit still changes depending on the manufacturer, bra style, and that brand's own sizing chart.
What's the difference between UK DD, E and US DDD?
DD and E are particularly confusing because different systems use these letters differently. A UK DD is commonly comparable to a US DD. However, after this point the systems begin to separate.
A UK E is commonly shown as approximately US DDD, or sometimes US DDD/F, depending on the brand. This means that seeing 34E on a UK bra does not mean you should automatically purchase a 34E from a US company. Always check which sizing system the retailer uses.
Some international retailers display more than one size on the same product page. Others provide a conversion chart. This is why checking the product's own size guide is especially important.
Worked examples
- UK 32D to US — generally a US 32D.
- UK 32DD to US — generally close to a US 32DD.
- UK 32E to US — approximately a US 32DDD/F.
- UK 32F to US — approximately a US 32G.
- UK 32FF to US — approximately a US 32H.
- UK 34G to US — approximately a US 34I.
These examples show why simply keeping the same cup letter can produce an incorrect result.
UK and US bra sizes are not always exact equivalents
There is an important limitation with any international bra size converter: a bra size is not only a label. The actual fit depends on the cup shape, wire width, band elasticity, fabric, bra construction and brand's pattern.
A 34G from one company can feel different from another 34G even when both use UK sizing. The problem becomes even greater when converting between countries, because the labels may be based on different sizing conventions.
Therefore, a converter should be used to find a starting size, not as a promise that one size will fit every bra — a point many simple conversion charts fail to explain.
How to check which sizing system a bra uses
Before ordering, look at the size list on the product page. A UK sizing range may contain cups such as:
DD, E, F, FF, G, GG, H, HH
A US sizing range may instead show:
DD, DDD, G, H, I, J, K
The presence of FF, GG or HH is a useful clue that the product is using UK-style sizing. However, do not rely on the letters alone — the safest option is always to read the manufacturer's own size chart.
Tip: If the cup conversion looks correct but the bra still doesn't fit, check the band and cup separately. Comfortable band, tight cups → size up the cup only. Comfortable cups, loose band → try a sister size instead.
How to use a UK to US bra size converter
If you already know your UK bra size, the process is straightforward.
Find your band, keep it
Locate your UK band number — it stays the same as your starting point for the US size.
Identify and convert the cup
Find your UK cup letter, then convert it using the UK-to-US chart above.
Check and compare
Check the US brand's own size guide, then compare it against your converted size.
Check the return policy
Before ordering, confirm returns are possible in case the converted size still isn't right.
For example, if your normal size is 36FF UK, a starting conversion would be approximately 36H US. Check whether the US manufacturer lists 36H and whether its own chart confirms that conversion.
Common UK to US bra size mistakes
One of the biggest mistakes is assuming that every letter means the same thing in both countries. Another is changing the band number during a simple UK-to-US conversion — in most standard charts, a UK 34 remains a US 34.
It's also easy to confuse UK E with US E, even though many US brands don't use E the same way, or to rely on an outdated conversion chart. Bra sizing can vary between manufacturers, and some brands use their own labelling conventions. Don't choose a bra only because the converted label looks familiar — your measurements and the manufacturer's size guide matter more than the letter alone.
Why a converter is useful for online shopping
A UK to US converter is particularly useful when buying lingerie internationally. You may normally shop from UK brands but find a particular style from a US retailer — without conversion, it's easy to order the same-looking cup letter and end up with a different cup volume.
It's especially useful for people who buy from several brands, since UK and US sizing can appear similar while becoming increasingly different at larger cup sizes.
Not sure of your UK size yet?
Start with our free UK bra size calculator — two measurements is all it takes to get your estimated band and cup.
Go to the calculatorFinal thoughts
A UK to US bra size converter makes international bra shopping easier, but the result should always be treated as an approximate equivalent. The main rule is simple: the band number usually stays the same, while the cup letter may change. The difference becomes more important after D and DD, where UK and US cup sequences follow different naming systems.
For example, a UK 32F is commonly around a US 32G, while a UK 34FF is around a US 34H. However, there is no universal conversion that guarantees the same fit across every lingerie brand — brand sizing, cup shape, fabric, underwire design and bra style can all affect fit.
For the most reliable result, use your UK size as the starting point, convert the cup, and then compare the result with the specific US brand's official size chart before purchasing.