Bra Size Chart

US & UK Cup Size Conversion

Cup size conversion between US, UK, EU, and AU systems is straightforward up to D, where all four systems use identical letters, but becomes increasingly complex above that point due to each system's distinct letter progression. The US system skips the standalone letter E and uses DD, DDD (also called F), then G through K. The UK system follows DD with E, F, FF, G, GG, H, HH, J, and JJ, employing double letters at regular intervals. The EU system uses a simple sequential alphabet with no doubled letters. Australian sizing mirrors the UK pattern. According to the European EN 13402 standard, which governs EU clothing sizes, cup letters should correspond to centimeter-based bust-to-underbust differences rather than the inch-based system used in the US and UK. This difference in measurement units compounds the letter-naming differences when shopping internationally. The most common conversion error occurs at the 6-inch difference point, highlighted in the table below, where a US DDD equals a UK E -- not a UK DDD, which does not exist in that system.

Band Size Conversion

Band size conversion is necessary because the five major regional sizing systems express the same underbust measurement in different units and scales. The US and UK systems both use inches, producing identical band numbers (28, 30, 32, and so on in two-inch increments). The European system, governed by EN 13402, converts to centimeters and increments by 5 (60, 65, 70, 75), where EU 75 corresponds to a US/UK 34. Australian sizing uses dress-size numbers (6, 8, 10, 12), with AU 12 equaling a US/UK 34 band. French, Belgian, and Spanish sizing adds 15 to the EU centimeter number, making a US 34 into a French 90. Italian sizing uses a numbered scale from 1 through 10, where each number maps to one EU increment. The band provides approximately 80% of a bra's structural support, so correct conversion is essential for fit -- a band that is too loose due to a conversion error shifts the support burden onto the straps, causing shoulder pain and reduced comfort. The table below maps every standard band size across all five systems.

How to Use These Charts

Using a bra size chart requires knowing your size in at least one system, then reading across the corresponding row to find the equivalent in any other regional standard. If you know your US size, locate it in the US column of the cup conversion table and the band conversion table, then read across to see the UK, EU, AU, French, and Italian equivalents. For example, a US 34DDD translates to UK 34E, EU 75F, AU 12E, and French 90F -- a single row in this bra size chart covers every major international system. If you do not know your size in any system, start by measuring your underbust and bust with a soft tape following the ASTM D6240 method, then use our bra size calculator to determine your baseline size before consulting the conversion tables. According to industry data compiled by Bratabase, incorrect size conversion is the leading cause of international lingerie returns, making a reliable bra size chart an essential reference for cross-border shopping from retailers in the UK, Europe, Australia, and Asia.

If you're not sure of your starting size, our bra size calculator will determine it from your measurements. To convert a single size quickly, use the interactive converter. For more detail on what each cup letter actually represents, see the breast size chart or cup size comparison.

Keep in mind that these standard sizes vary by brand -- see our brand sizing guide for how specific labels differ. Not sure which international size is yours? Our bra size converter lets you translate between any system instantly.

Why Bra Sizes Vary Between Countries

The variation in bra sizing across countries stems from the independent development of measurement systems before any international standardization effort existed. The United States and United Kingdom both adopted inch-based systems in the early 20th century and share identical band numbers, but cup letter progression diverged after DD when UK manufacturers introduced the double-letter system (FF, GG, HH) while US brands stuck with single letters (F, G, H). Continental Europe moved to centimeter-based bands in the 1990s under the EN 13402 framework, producing the 65-70-75-80 sequence that differs from the US-UK 28-30-32-34 numbering. Australia adopted UK cup lettering but mapped bands to dress sizes, creating yet another translation layer. These independent histories mean that no single bra size chart can be treated as universal -- each system must be cross-referenced. The tables above provide that cross-reference for every standard band and cup size in use across the five major regional systems.

Save this bra size chart for quick reference when shopping online or in store. Find your size with our free bra size calculator. Sports bras often use a different sizing system -- our sports bra size calculator converts your chart size for workout wear, and our sports bra vs regular bra comparison explains the structural differences. For teens in the 26-32 band range, our teen bra guide covers the smaller sizes that are under-represented in many charts. Your breast shape also affects how a size from this chart fits in practice.