Understanding International Bra Sizing
Why Do Bra Sizes Differ by Country?
Bra sizing systems evolved independently in different regions, leading to different band numbering and cup letter conventions. A US 34C, a UK 34C, an EU 75C, and a French 90C all represent roughly the same body measurements — but the numbers and letters differ.
The Major Sizing Systems
US/UK: Band size is the underbust measurement in inches rounded to the nearest even number (28, 30, 32, 34, etc.). Cup letters progress A, B, C, D, DD, DDD (US) or D, DD, E, F, FF (UK).
EU: Band size is the underbust measurement in centimeters rounded to the nearest multiple of 5 (60, 65, 70, 75, etc.). Cup letters are A through K without double letters.
FR/BE: Same as EU but the band number is EU + 15 (so EU 75 = FR 90).
IT: Uses a simple number system (1–7) for bands, where 1 = 32″, 2 = 34″, etc. Cup letters follow EU convention.
AU/NZ: Uses the same band and cup convention as the UK/US system.
JP: Band size is underbust in cm (same as EU). Cups start from A (no AA) and go through I.
BR: Same as EU sizing for both band and cup.
How Conversion Works
All systems are based on the same physical measurements. The band corresponds to underbust circumference, and the cup size represents the difference between bust and underbust. Our converter uses the EN 13402 standard and established industry conversion tables to ensure accuracy.
Why International Bra Size Conversion Matters
In today's global e-commerce market, buying lingerie from international retailers has become commonplace. However, the lack of a universal bra sizing standard means that a size that fits perfectly from a US brand may not have the same label when shopping from a UK, European, or Japanese brand. Understanding international bra size conversion is essential for making informed purchases and avoiding costly returns.
The confusion stems from historical development: each country created its sizing system independently based on different measurement traditions, body type assumptions, and manufacturing standards. While the International Organization for Standardization published EN 13402 for clothing sizes, bra sizing still varies significantly across regions.
US vs UK Sizing — The Cup Letter Split
The most impactful difference between US and UK bra sizing is in the cup letters beyond D. In the US system, manufacturers use DD, DDD (sometimes F), and G. The UK system instead uses DD, E, F, FF, G, GG, H, HH, and beyond — alternating single and double letters. This means a US DDD is a UK E, and a US G could be either a UK F or FF depending on the brand.
Band sizing between US and UK is identical — both use even inches (28, 30, 32, etc.). This makes conversion simple for band sizes but potentially confusing for cups above D. When shopping from UK brands like Bravissimo, Panache, or Freya, always check the cup letter mapping carefully.
European Sizing (EN 13402)
The European system measures the band in centimeters, rounded to the nearest multiple of 5. To convert from US/UK to EU: multiply the inch measurement by 2.5 and round to the nearest 5. For example, 34 inches × 2.5 = 85 cm → EU 85. The cup letters in the EU system follow a simple progression: A, B, C, D, E, F, G, H, I, J, K — no double letters at all. This means US DD = EU E, and US DDD = EU F.
French, Belgian and Spanish Sizing
France, Belgium and Spain share a sizing convention that adds 15 to the EU band measurement. So an EU 75 band becomes a FR 90 band. The cup letters follow the EU system exactly. This means a US 34DD converts to EU 75E which converts to FR 90E. The +15 offset for the band is a historical convention from French dressmaking that persists to this day.
Japanese and Australian Sizing
Japan uses centimeter-based bands identical to the EU system (60, 65, 70, 75, 80, 85) but their cup progression starts at A rather than AA — there is no AA cup in the Japanese system. Japan also tends to have a more limited range of sizes, typically offering bands from 60 to 85 and cups from A to I. Australian and New Zealand bra sizing is identical to the UK system in terms of both band and cup measurements, though some Australian brands may use dress-size equivalents (AU 10 = 32, AU 12 = 34, AU 14 = 36).
Brazilian Sizing
Brazil follows the EU system for band sizing (centimeters, multiples of 5) and uses the same EU cup letter progression. However, Brazilian brands often have their own size charts that may vary slightly. When shopping from Brazilian brands, it's safest to use the EU conversion and then check the specific brand's chart if available.
Tips for Accurate Conversion
Always measure yourself before converting, rather than converting from a size you believe you wear. Many women are wearing the wrong size to begin with. Use a soft measuring tape, measure your underbust and overbust, then use our converter to see your size in all 8 systems simultaneously. Remember that conversion is approximate — actual fit depends on the brand, style, material, and your individual body shape. When possible, try before you buy, especially from unfamiliar brands or countries.