Convert bra size between US, UK and EU regions

This converter takes one complete size in the US, UK, or EU system and returns the corresponding label in all three regions. It uses a fixed conversion table rather than a rough arithmetic guess, handling both the band number and the different cup progressions. Enter a regional system and a size such as 34DD or 75E to receive consistent, easy-to-compare results.

Enter the label exactly as it appears

Start by selecting the system printed on the garment or stated by the retailer: US, UK, or EU. Then enter the full size with its numeric band first and alphabetic cup second. A space between them is accepted, so both 34DD and 34 DD work. The source system matters because identical-looking cup letters can occupy different positions in regional progressions. For example, the UK sequence introduces doubled letters such as FF and GG, while the EU sequence normally advances through single letters after D. The converter parses the label as one size, validates both parts against the chosen system, and uses their positions in the relevant tables. It does not infer a region from the number because that could make an apparently reasonable but incorrect choice. If a store merely says “international sizing,” check its own chart or product description before converting. Providing the declared source system is the safest way to preserve the intended band and cup volume.

Understand how the conversion is calculated

Band and cup are converted as two coordinated table positions. US and UK band labels use the same even-number ladder in the supported range, while EU labels use the corresponding five-centimetre steps. Thus a 34 band occupies the same position as an EU 75 band. Cup conversion is not performed by copying the letters. Instead, the source cup is located on that region’s ordered volume ladder, and the label at the same position is selected from each target ladder. This distinction becomes especially important above D. A US DDD, UK E, and EU F share one position in the table used here, although their printed names differ. The result includes US, UK, and EU labels every time, including the original region in normalized form, which makes comparisons straightforward. Conversion tables are useful starting points rather than manufacturing standards: individual brands may grade bands, cup depth, wire shape, and fabric tension differently. Always consider the retailer’s own fit notes when choosing a product.

Check the result before buying

Use the converted label to search a regional catalogue, compare a retailer’s chart, or communicate a known size to customer support. Keep in mind that a nominal equivalent does not guarantee an identical fit. Cup shape, wire width, strap placement, stretch, and brand-specific grading can change how two bras feel even when their table positions match. If you are between sizes, trying the converted size alongside nearby sister sizes may be useful, but sister sizing is a separate adjustment and is not performed by this tool. The converter deliberately rejects malformed strings, odd or unsupported bands, and cups that do not belong to the selected regional ladder. That strict behavior prevents a typo from silently becoming a plausible result. When an error appears, verify the region, remove unrelated words, and enter only the band and cup. For labels outside the supported table, use the manufacturer’s chart, since extended-size conventions vary more widely. The API version costs $0.002 per item and returns the same deterministic table conversion used in the browser.