How to Convert Bra Size Between US, UK, and EU Systems

3 月 6, 2026 Updated 7 月 16, 2026 4 min read Shopping Advice

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Three Systems, One Body

US, UK, and EU bra labels describe the same body using different number and letter conventions. Converting well means separating band translation from cup translation, then verifying with fresh measurements. Copying “34D” onto a EU product page without conversion is a frequent cause of returns.

Many women report keeping a notes app row for each overseas brand that fits. Industry estimates often suggest that mapping bust-minus-band difference beats letter matching for cup accuracy.

US to UK: Often Similar Bands, Diverging Cups at DD+

Bands often align numerically (34 US vs 34 UK) for many brands, but cup progressions split after D. US DD may align with UK DD in some charts but US DDD/E may map to UK E or F depending on publisher. Always read the brand’s dual chart if provided.

US/UK to EU: Band Centimeters

EU bands use 65, 70, 75, 80, 85 cm labels tied to underbust. Approximate: US 34 ≈ EU 75, US 36 ≈ EU 80. Exact mapping varies by brand tolerance of ±2 cm.

Cup Conversion by Difference, Not Letter

  1. Measure underbust and bust in cm or inches consistently.
  2. Compute difference.
  3. Apply US, UK, and EU cup tables to the same difference separately.
  4. Combine each cup with the converted band for three full sizes to try.

Our conversion calculator automates this.

Worked Example (Illustrative)

Suppose underbust 30 in and bust 37 in in US method yields 34C as starting point. EU band might center on 75; cup letter from cm difference may be D or E depending on chart—proof that manual letter copy fails.

Shopping Checklist for International Orders

  • Screenshot brand size chart at time of purchase
  • Check return window and restocking fees
  • Order band and cup neighbors if budget allows
  • Read fit reviews mentioning “runs small in cup”

UK Double Letters Explained

UK continues FF, GG, HH where US may use G, H, I or mixed DD/E labels. Extended cup shoppers should use extended conversion tables on conversion chart page.

When Conversion Is Not Enough

Shape mismatch persists across converted sizes—try different cup cut or brand. Remeasure if body changed since reference bra fit.

Sister Sizes After Conversion

Convert base size, then apply sister sizing in the target system—not the origin system. See sister sizes explained.

Brand Variance Disclaimer

Even domestic brands disagree; international conversion adds steps, not certainty. Treat outputs as short lists to try, not one immutable label.

Marketplace Listings and Mixed Labels

Third-party sellers on global marketplaces sometimes mix US and UK tags on the same listing photo. Verify the tag in product images and message the seller if unclear. When in doubt, order based on your cm measurements translated through our calculator rather than the listing title alone.

Documenting Successful Conversions

When a converted size works, save the order confirmation size, brand, and your underlying measurements. Failed conversions are equally valuable notes—”Brand Z EU 75F too shallow; try G next” speeds future attempts.

Travel Shopping Tips

Airport and tourist shopping often stocks limited sizes. Know your US, UK, and EU triple before traveling so you can grab opportunistic finds without guessing under time pressure. Sister sizes apply after conversion in the local system you are buying.

Subtitle and Dubbing on Product Videos

Video reviews may call out UK sizes while you wear US. Pause and map letters using difference method rather than assuming the reviewer shares your label even if cup volume looks similar on camera.

Outlet and Past-Season Stock

Outlet tags may list multiple regional sizes on one hanger. Verify active label, not outlet markdown stickers layered on top. Clearance is worthwhile only if conversion and return policy still protect you when fit fails.

Secondhand Marketplaces

Resale listings often omit original size chart photos. Ask sellers for tag close-ups and compare listed size to your conversion cheat sheet before buying. Pre-owned bras may also be stretched—factor elastic wear into expected fit.

Chat Support and Live Agents

When emailing brand support, paste measured cm underbust and cm bust plus your computed US/UK/EU triple. Agents resolve sizing tickets faster with numbers than with “usually a medium” descriptions.

Customs Forms and Declared Value

International returns sometimes require declared garment value on labels. Keep conversion notes with order invoices so repurchasing the correct converted size after a return does not repeat the same mistake.

Need a Size Check After Reading?

Use our bra size tools to turn the advice in this article into a practical starting size, compare sister sizes, or convert sizes across different markets.

Bra Size Calculator Sister Size Calculator

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