Bra Size Chart: US, UK and EU Sizes Explained

September 28, 2026 · 9 min read

A 34C in New York, a 34C in London, and a 75C in Paris describe roughly the same body — but only roughly. Bra sizing is split into three main systems (US, UK, and EU), and while they share the same basic structure of band-plus-cup, their cup letter progressions and band numbering differ in ways that genuinely matter once you shop across borders. This guide lays out each system with full charts, explains exactly where they diverge, and shows you how to convert between them without the guesswork.

If you haven't measured yet, start with our measuring guide and bra size calculator — conversions only help once you know your starting size.

Why Different Sizing Systems Exist

Bra sizing grew up regionally. American manufacturers, British manufacturers, and continental European manufacturers each standardised on their own conventions decades ago, and none of them ever converged. The result is three systems that look interchangeable at first glance — they all use a number for the band and a letter for the cup — but quietly disagree in two places:

• Band numbering. The US and UK number bands in inches (28, 30, 32, 34...), based on the underbust measurement. The EU numbers bands in centimetres, roughly speaking (60, 65, 70, 75...) — so a US/UK 34 band is labelled 75 in the EU.
• Cup letters above DD. Up to a D cup, US, UK, and EU letters all match. Above DD, the UK system inserts extra letters (E, F, FF, G...) while the US system skips straight from DDD to G. This is the single biggest source of cross-border confusion.

There is also no single global authority enforcing any of these systems. Individual brands adjust their cuts, grade their patterns differently, and sometimes invent their own letter sequences. Charts and conversions are therefore best treated as strong guides, not universal truths — always check the brand's own size chart when you can.

US Bra Size Chart

In US sizing, the band is your underbust rounded to the nearest even inch, and each inch of difference between bust and band is one cup step. The US cup sequence runs: AA, A, B, C, D, DD, DDD, G, H, I, J. Note the jump from DDD directly to G — there is no E or F in standard US labelling.

How to read it: find your band number at the top, then follow the column down to the row with your cup letter. A 36-inch band with a D cup is a 36D in US sizing. For a version of this chart with guided measuring, see our US bra size calculator.

UK Bra Size Chart

UK sizing uses the same inch-based bands as the US, and cups match the US exactly through DD. Above DD, the UK system uses a finer progression: DD, then E, F, FF, G, GG, H, HH, J. This means a UK E is the same volume as a US DDD, and a UK F matches a US G.

How to read it: the same as the US chart — band across the top, cup down the side. The extra UK letters (E, F, FF, GG, HH) give more granular steps in larger cup sizes, which is one reason some people prefer UK sizing. Our UK bra size calculator walks through the UK system in detail.

EU Bra Size Chart

EU sizing keeps the same cup-letter idea but numbers the band in centimetres. In practice, the EU band number is the underbust measurement in centimetres rounded to the nearest 5: a 75 band suits an underbust of roughly 73–77 cm. EU cup letters generally follow the sequence AA, A, B, C, D, E, F, G, H..., similar in spirit to the UK letters, but EU brands are the least standardised of the three systems — always treat EU conversions as approximate.

A note of caution: some EU brands label cups differently (a few use the UK-style double letters, others don't), and French and Spanish brands historically used their own numbering. When buying from an EU brand, the brand's own chart beats any generic conversion table.

US, UK and EU Conversion Table

This table shows equivalent sizes across the three systems for common sizes. Remember: these are standard conversions, not promises — brands vary.

The pattern is consistent: bands convert by unit (34 in → 75 EU), while cups convert by letter position. US and UK cups are identical through DD; above DD, count the steps: US DDD = UK E, US G = UK F, US H = UK FF, and so on. EU cups in the table above follow the same step positions as UK cups.

Key Differences Between the Systems

Cup progression above DD

This is the difference that trips people up most. Side by side:

• US: D → DD → DDD → G → H → I → J
• UK: D → DD → E → F → FF → G → GG → H → HH → J

A US DDD and a UK E are the same cup volume; a US G and a UK F are the same volume. The letters differ, the inches of difference don't. If you remember only one thing from this guide, make it this.

Band numbering: inches vs centimetres

US and UK bands are inch-based even numbers (28–44+). EU bands are centimetre-based numbers in steps of 5 (60–100+). The conversion is mechanical: measure your underbust in centimetres, round to the nearest 5, and that's your EU band. A 34-inch underbust is about 86 cm, but the corresponding EU band is 75, because EU bands are sized roughly 10–11 cm below the actual underbust centimetres — the band is meant to stretch to fit. This is why you convert via the inch band (34 → 75) rather than by measuring centimetres directly against the EU number.

Brand variation is real

Even within one system, two brands can cut a "34C" differently. Grading (how a pattern scales between sizes), fabric stretch, wire shape, and cup depth all affect fit. Generic charts describe the systems; individual brands describe their own garments. When a brand publishes its own chart, trust it over any generic table — including this one.

How to Use Conversions When Shopping

1. Know your home-system size first. Measure properly (measuring guide) and get your estimated size in the system you know best.
2. Convert the letters, not just the band. Shoppers often convert 34 to 75 and forget the cup letters differ. A US 34DDD becomes a UK 34E and an EU 75E — the whole size converts, not just the number.
3. Check the retailer's sizing note. Many international retailers state which system their labels use. A UK retailer selling a "34E" means the UK E (US DDD). A US retailer selling a "34DDD" means the US DDD (UK E). Same garment, different label.
4. Order two sizes when between systems. If you're trying a brand from another sizing system for the first time, ordering your converted size plus one neighbouring size (a sister size up or down) removes most of the gamble.
5. Try the fit, not the label. However you converted, judge the bra on your body: the band should be snug and level, the cups should contain without spilling or gaping, and the centre front should sit flat against your sternum.

To double-check a conversion interactively, use our sister size calculator alongside the charts, or run your measurements through the bra size calculator — pick your country in the dropdown — and compare the results.

Frequently Asked Questions

Is a US 34DDD the same as a UK 34E?

Yes — they represent the same cup volume on the same band. The US system labels the step after DD as DDD, while the UK system labels it E. The same relationship holds further up: US G = UK F, US H = UK FF, and so on.

How do I convert a US band size to an EU band size?

Convert via the inch band rather than measuring centimetres directly: US/UK 32 becomes EU 70, 34 becomes 75, 36 becomes 80, 38 becomes 85, and so on. The EU number is roughly the underbust in centimetres minus 10–11, rounded to the nearest 5.

Are cup sizes the same across US, UK and EU?

They match through D cup: a C is a C in all three systems. Above DD, US and UK letters diverge (US DDD = UK E), and EU brands are the least standardised, so treat EU cup conversions as approximate and check the brand's own chart.

Why do brands from different countries fit differently in the same labelled size?

There is no single global standard, so each brand grades its patterns its own way. Fabric stretch, wire shape, and cup depth also change the fit. A generic conversion table describes the sizing systems; the brand's own chart describes its garments — trust the brand's chart when they conflict.

Which sizing system should I use when ordering online?

Use the system the retailer labels in. Check the product page or size guide for whether sizes are listed in US, UK, or EU sizing, convert your known size into that system, and when in doubt order your converted size plus one neighbouring size so you can compare the fit at home.

Try It Yourself

Reading about sizing is useful — measuring is better. Grab a tape measure, take your two measurements, and get your estimated size in under a minute.