Shopping for bras from international brands has never been easier — but the sizing has never been more confusing. A bra from a US brand, a French lingerie label, or an Australian retailer will use a completely different sizing system from the UK standard, and simply guessing can leave you with something that does not fit at all and is expensive to return.

This complete guide explains every major bra size conversion — UK to US, UK to EU, UK to French, UK to Australian — with practical tables and tips for shopping from international brands.

Why Bra Sizes Differ Between Countries

There is no international standard for bra sizing. Each country or region developed its own conventions, which means the same physical bra might be labelled completely differently depending on where it was made. The differences appear in both the band size (the number) and the cup size (the letter), which makes conversion more complex than simply adjusting one figure.

The most important thing to understand before comparing sizes is that UK cup sizing uses a different progression from most other systems. UK sizing includes double-letter cups (DD, FF, GG, HH) between single letters, creating a finer graduation. Many other countries skip these intermediate sizes, which is where the confusion typically starts.

UK vs US Bra Sizes

UK and US bra sizes appear almost identical at first glance — both use inches for the band and letters for the cup — but the cup progressions diverge from DD upward.

UK to US Cup Size Conversion

Band sizes are measured in the same inches, so a UK 34 and a US 34 band are nominally the same measurement. However, individual brands may still run differently in practice, so always check brand-specific size guides where available.

Practical Example: UK to US

If you are a UK 34FF and want to order from a US brand, you would typically look for a US 34H. If the US brand does not stock H cups, check their size guide — some larger US brands have expanded their cup range, but many still stop at DDD or F.

UK vs EU Bra Sizes

European bra sizes use centimetres rather than inches for the band and a different letter system for the cup. The band size conversion is therefore a simple mathematical calculation, while the cup conversion requires a chart.

UK to EU Band Size Conversions

UK to EU Cup Size Conversions

Practical Example: UK to EU

A UK 36DD would convert to an EU 80E. A UK 32F would become an EU 70G. Always double-check with the specific brand's size guide, as some European brands (particularly German and French ones) may use slight variations.

UK vs French Bra Sizes

French sizing is used by many luxury lingerie brands, including well-known French and Italian labels available in the UK. The band conversion is different from general EU sizing.

French Band Size Conversions

The cup sizing for French brands generally follows the same letter progression as general EU sizing (A, B, C, D, E, F, G, H) without double letters. Cup letter conversions are the same as the UK-to-EU table above.

UK vs Australian Bra Sizes

Australian bra sizing is very similar to UK sizing, which makes conversions relatively straightforward. However, Australian band sizes are typically 2 numbers larger than their UK equivalents.

UK to Australian Band Size Conversions

Australian cup sizes generally follow the same single and double-letter progression as UK cups, so a UK 34E would be approximately an AU 16E — the band number changes but the cup letter usually stays the same.

Buying From Further Afield: Japan, China, Korea, India, Pakistan & Canada

Beyond the US, EU, France and Australia, a few other markets come up often enough to be worth a quick note.

Japan

Japan uses its own JIS L 4006 standard, followed by brands including Wacoal Japan, Triumph Japan and Uniqlo. Band size is your underbust in centimetres, rounded to the nearest 5 (60, 65, 70, 75, 80…), and cup letters run AAA, AA, A, B, C, D, E, F, G, H in 2.5cm steps of difference — broadly similar logic to the UK, just in centimetres throughout and with the letter written before the number (for example, "C70" rather than "70C").

China

Chinese sizing also bands in centimetres, rounding the underbust to the nearest 5cm, with a cup letter sequence very close to the UK's up to D. Above D, conventions can shift by a letter depending on the brand, similar to the UK-to-US jump — so it's worth double-checking a specific retailer's chart rather than assuming a straight match.

Korea

South Korean sizing generally follows the same centimetre-and-letter logic as Japan, since both markets were influenced by the same standard. As with Japan, expect the band in cm and a broadly familiar cup letter sequence, with brand-level variation.

India & Pakistan

Both markets commonly use UK-style inch-based band sizing with familiar cup letters (A, B, C, D, DD…), a legacy of historical UK retail influence, though local and international brands sold in both countries can differ. Your UK size is usually the most useful starting point here.

Canada

Canadian bra sizing follows the US system exactly — band and cup both convert the same way as the UK-to-US table above, with no separate Canadian conversion needed.

For any of these markets, the same rule applies as everywhere else in this guide: treat the conversion as your starting point, and check the specific brand's own size chart before ordering, since cup depth and band construction vary by manufacturer regardless of the labelling system.

Shopping Tips When Buying From International Brands

Always Use the Brand's Own Size Guide

Generic conversion charts give you a strong starting point, but individual brands do not always follow the standard exactly. Whenever you are buying from an international brand for the first time, look for their specific size chart on their website.

Measure in Centimetres as Well as Inches

Many international size guides ask for your measurements directly in centimetres. It is worth noting both your inch and centimetre measurements when you first measure yourself, so you have both on hand. Our bra size calculator gives you your size in multiple formats to make international shopping easier.

Know Your Sister Sizes

When ordering internationally, knowing your sister sizes gives you options. If a US brand does not stock your exact converted size, the adjacent sister size (one band up or down) is the most logical alternative to try.

Be Aware of Fit Differences Beyond Size

European bras, and particularly French lingerie brands, often have different underwire shapes, cup depths, and construction from UK brands. A size that converts correctly on paper may still fit differently because of these stylistic differences. Be willing to experiment with the adjacent size if the converted size does not feel right. Check our guide on signs your bra does not fit if you receive a bra that feels off despite having the right converted size.

The Easiest Way to Start: Know Your UK Size

Before any international conversion is possible, you need to know your UK size accurately. If you are not confident in your current size, or if it has been some time since you measured properly, start with our guide on how to measure your bra size at home and then use the conversion tables in this article to shop from whichever brand or country you like.

Getting international sizing right is mostly a matter of knowing your measurements, understanding the conversion for that specific country, and allowing for a small amount of brand-to-brand variation. Once you have that knowledge, a much wider world of beautiful lingerie opens up.

Ready to find your perfect bra size? Try our free UK calculator.

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