UK vs US vs EU Bra Size Conversion: US Bra Sizes vs UK Bra Sizes and the EU Letters Between Them

Shop a British brand from the United States and the label stops behaving. Your band number survives the trip, your cup letter does not, and past a DD the two ladders part company. This guide translates US bra sizes vs UK bra sizes and the European system beside them, with full bra size conversion chart tables for bands and cups, and one difference from the generic converter pages: where brand charts disagree, we print the disagreement instead of hiding it.

Quick Answer

Band numbers are the easy half. Cup letters are the trap. Convert in this order:

1. Band: US and UK band numbers are identical, so a 34 stays a 34. The same band is a 75 in EU sizing, a 90 in French and Spanish sizing, and a 12 in Australian sizing.
2. Cups to DD: US, UK and EU letters match exactly through D, and a DD is a DD in the US and UK (an E in EU letters).
3. Cups past DD: stop reading letters and start counting steps. A UK E is a US DDD, a UK FF is a US H, and a UK H is a US K. The full ladder is in the cup table below.

One worked translation to hold in your head: a UK 36FF is a US 36H and an EU 80H. Same body, same band, three spellings. And one warning that matters more than any table: a converted size is a starting size, not a promise, because brands cut cups differently even inside one system. If you have not measured lately, start with our guide to calculating your proper bra size and convert from a size you trust.

Why three systems exist at all

There is no international bra sizing standard, and there never has been. Each region built its labels around its own tape measure. The US and UK systems grew up in inches, which is why their band numbers still match, in even steps of two. Continental Europe measured in centimeters and built bands in steps of five, so EU labels run 65, 70, 75 and up. France and Spain then took the EU number and added 15, which is why a French 90 is not a bigger bra than a European 75; it is the same bra wearing a different number.

Cups split for a sillier reason. Every system starts at A and climbs one cup volume at a time, but each region chose its own spelling for the climb. The UK doubled some letters (DD, FF, GG, HH). The US stacked Ds first (DD, DDD) and then rejoined the alphabet at G. Europe walked the alphabet one letter at a time. Three spellings, one staircase. Once you see the staircase, international bra size conversion stops being memorization and becomes counting.

The band rule: the number matches, the tape is not the label

UK bra sizes explained in one line: the band number is shared with the US, full stop. A UK 34 band and a US 34 band are cut for the same ribcage. What changes across the Atlantic is only the cup letter, covered in the next section.

European bands need one idea, and it saves real money: the EU number is a label, not your measurement. A 34 inch underbust is about 86 cm, and readers who convert inches to centimeters and then shop for an 85 or 90 band buy a bra two sizes too big. EU bands step in fives and sit close to, but not exactly on, the underbust in centimeters; a 75 is cut for roughly a 73 to 77 cm underbust, and the unstretched band measures shorter still, because elastic is supposed to stretch onto the body. Treat bra size measurement cm vs inches as two label systems to translate with a table, never as a unit conversion to do in your head.

Band table built from the international band chart at HerRoom, checked 3 November 2026, and cross checked against the Chantelle size guide’s AU, US, UK and EU band rows. The Australian column is the simple arithmetic readers expect: the AU band is the US or UK band minus 22.

US bra sizes vs UK bra sizes: the cup trap

Here is the whole problem in one sentence: the two ladders are identical through DD and strangers after it. A 34D is a 34D in London and in New York, and a 34DD is a 34DD in both. Then the UK climbs E, F, FF, G, GG, while the US climbs DDD, G, H, I, J, and the same letter starts naming different volumes. A UK G and a US G are two cup steps apart, which is why a converted order can arrive feeling wildly wrong even when the band was done perfectly.

The honest way to print this is by cup step: the number of inches of difference between full bust and band, which is the spine every brand chart is built on. Read across a row to see one cup volume in its three spellings.

Cup table built from the international cup chart at HerRoom, checked 3 November 2026, and cross checked against brand ladders: the UK column matches the Elomi ladder and the EU column matches the Chantelle ladder in retailer size guides. The parenthetical US labels are the disagreement, printed on purpose: US brands do not agree on what to call steps 5 to 7, so one cup leaves the factory as a DD, DDD or DDDD in one catalogue and as an E, F or G in another.

Two reading rules make the table safe to use. First, convert by step, not by letter: find your cup in your home column, move straight across the row, and take the letter in the new column, even when it looks wrong. Second, trust the brand’s own chart over this page: HerRoom itself warns that its European letters follow one convention and are not universal across European brands. Where a brand chart and a general chart conflict, the brand chart describes the bra you are actually buying. The UK brands readers shop most with this table are walked through in our Elomi guide and Panache guide.

European bra sizes explained

European bra sizes explained in the order a shopper meets them: centimeter bands in steps of five, then a cup ladder with no doubled letters at all. The EU cup at step 5 is an E where the UK and US print DD, and from there the EU letter is simply the step spelled alphabetically: F at step 6, G at step 7, H at step 8, on through the alphabet. That is why how to convert UK bra size to US feels harder than converting either one to EU: the European ladder is the only one of the three that never doubles back on itself.

Two variants ride on the EU system. France and Spain add 15 to the band number and keep EU cup letters, so a French 90F is a European 75F with a bigger number on the band and the same cup. French brands sold in the US, Chantelle among them, often print several systems on one tag, which makes their tags the safest place to check your arithmetic. Italy replaces the band with a small number, running 0 at a 30 band up to 9 at a 48, with EU style cup letters; Italian labels are rare in US stores, but they surface on imported lines and confuse shoppers because a “2” looks like a dress size. Australia and New Zealand borrow the UK cup ladder whole and swap the band for a dress size number, the minus 22 column in the band table above.

One caveat belongs in bold: not every European brand climbs the same ladder. Some skip the letter I, some stop at H, and HerRoom flags that its EU column is a convention, not a law. The system gets you to the right neighborhood; the brand chart picks the house.

Three conversions, worked slowly

UK 36FF to US and EU. Band first: 36 stays 36 in the US, becomes 80 in EU and 95 in French sizing. Cup: FF sits at step 8, which reads across to a US H and an EU H. Final answer: US 36H, EU 80H, FR 95H. This is the conversion that breaks most often, because a shopper who keeps the letters settles for a US 36G that is a full step small.

US 34DDD to UK. Band: 34 in both systems. Cup: DDD is step 6, which reads across to a UK E and an EU F. Final answer: UK 34E, EU 75F, FR 90F. Elomi, Freya and Panache shoppers live on this row.

EU 75F to UK and US. Band: 75 becomes 34. Cup: EU F is step 6, so UK 34E, US 34DDD (or a US 34F from a brand that labels step 6 that way). Two examples land on step 6 for a reason: it is the busiest border crossing in bra sizing, the first step past DD, where all three systems spell one volume three ways.

Why the converted size still fits differently by brand

Ask why do different bra brands fit differently and the honest answer is that the label was never the whole bra. Two bras in a converted 34E can differ in cup width, cup depth, wire shape and band firmness, because each brand cuts for its own fit model. UK full bust brands tend to build narrower, more projected cups; many US brands cut wider and shallower at the same letter. Neither is wrong. They are different shapes wearing the same label, which is why how to convert bra sizes between brands ends with fitting, not arithmetic.

So work like a fitter. Convert to a starting size, then adjust with sister sizes. If the cups fit and the band rides up, go a band down and a cup up; if the band is right and the cups gape, drop a cup step in the same system before you re-convert anything. Our sister sizes explained guide walks the trade with a full chart. Sports bras add one wrinkle: UK sports brands such as Shock Absorber size firmly on purpose, covered in our Shock Absorber guide. And when a bra is sold in S, M and L, put the tables away: alpha sizing converts from your measurements, not from your bra size, as alpha sizes vs bra sizes shows. Once the size is translated, our guide to the best bras for everyday wear is the shopping next step.

Common Mistakes

Mistake 1: Converting centimeters as if they were inches. A 34 inch underbust is about 86 cm, but the EU band for that body is a 75, not an 85. Fix: translate the band with the band table; never convert the unit and shop the result.

Mistake 2: Keeping your cup letter past DD. A UK 34G ordered as a US 34G arrives a full two steps small. Fix: find your step in the cup table and read across the row, however odd the new letter looks.

Mistake 3: Assuming DDD and F are different sizes. In US catalogues they are usually two names for step 6, and a UK F is a different, larger cup than both. Fix: match a US brand’s DDD to the UK E, and verify any F claim on its own chart.

Mistake 4: Converting from a bra that never fit. A conversion faithfully translates a wrong size into three wrong sizes. Fix: measure first with our measurement guide, settle your home size, then convert.

Mistake 5: Ordering one converted size with no backup. Brand variance means your converted size is the center of a range, not a bullseye. Fix: where returns allow, order the conversion and one sister size, and keep the one that passes the fit checks.

Mistake 6: Reading a French band as a European band. A French 90 is a European 75; shop it as a 90 in EU and the band swallows you. Fix: subtract 15 from any French or Spanish band before it goes near an EU chart.

Frequently Asked Questions

Is a UK H cup the same as a US H cup?

No, and this is the sharpest version of the trap. A UK H sits at step 11, which the US ladder spells K. A US H is step 8, a UK FF. Same letter, three steps apart, which is why fuller bust shoppers should convert by step every time.

Do Australian sizes follow the UK or the US?

Both, split down the middle. Australian cups follow the UK ladder letter for letter, while Australian bands use dress size numbers, the US or UK band minus 22. An Australian 14FF is a UK 36FF and a US 36H.

My size is a letter like M. Can I convert that?

Not from the letter. An M is a brand specific average of several band and cup sizes, and two brands’ M can cover different bodies. Convert from your underbust and full bust measurements instead, using the brand’s own alpha chart; our alpha sizes vs bra sizes guide shows how much range one letter hides.

The brand’s own chart disagrees with the table here. Which one wins?

The brand’s chart, every time. General charts translate between systems; the brand chart describes the actual bra, including its house quirks. Use this page to find the size to try first and the brand page to confirm it before you pay for shipping.

Can I convert a sports bra size the same way?

The labels convert the same way, but the fit target does not. Sports bands are cut to hold still under load and UK sports brands run firm, so a converted size that works in an everyday bra may want its sister size in a sports style. Convert, then fit check it like a sports bra.

Key Takeaways

• Bands: US and UK numbers are identical; EU is the centimeter label (34 = 75), France and Spain add 15 (90), Australia subtracts 22 (12).
• Cups match through DD in the US and UK; the EU calls that step an E.
• Past DD, count steps, never letters: UK E = US DDD, UK FF = US H, UK H = US K.
• The EU number is a label, not your underbust in centimeters. Converting units and shopping the result buys the wrong band.
• A converted size is a starting size. Brand shape decides the final fit; sister sizes are the adjustment tool.
• Where charts conflict, the brand’s own chart wins.

Sources

• HerRoom: international band and cup conversion charts, including the Universal Cup Sizing ladder and its own warning that European cup letters vary by brand. Checked 3 November 2026.
• Chantelle size guide, as republished in the David Jones size guide library: AU, US, UK and EU band rows cross checked against the band table. Checked 3 November 2026.
• Brand cup ladders for Elomi (UK) and Chantelle (EU), as published in retailer size guides and summarized at Niidor: step by step cup spellings cross checked against the cup table. Checked 3 November 2026.
• HauteFlair: independent conversion reference whose UK and US worked examples (UK 34E = US 34DDD, UK 34F = US 34G, UK 28FF = US 28H) match the cup table row for row. Checked 3 November 2026.