Bra Size Calculator

International Bra Size Conversion Guide

Translate calculator results across UK, US, EU, FR, JP, and AU systems without losing accuracy. Prepare for cross-border shopping with downloadable tools and brand-specific tips.

Get my base sizeCheck sister sizes

How to approach global conversions

The calculator gives you an accurate band and cup baseline. Use the workflow below to convert that result for any retailer or region without guesswork.

  1. Measure snug underbust and bust, run the calculator, and record values in inches and centimetres.
  2. Identify sister sizes so you can move up or down a band when regional bands skip your exact number.
  3. Pull the conversion chart for each brand before checkout and verify cup progression (single vs double letters).
  4. Log your order country, currency, and the equivalent size you selected in the measurement log template.
  5. After delivery, note any fit deviations so the next international purchase is faster.

Regional sizing highlights

United Kingdom (UK)

Uses inches for band length, adds 0–2 inches to get the labelled band (e.g., a snug 32" underbust → band 32). Cup progression adds letters (DD, E, F, FF, G…).

  • Expect double letters beyond D.
  • Most UK brands share grading but verify unique jumps (e.g., FF vs GG).

United States (US)

Also inch-based bands but cup progression typically uses single letters with occasional double letters (DD, DDD/F).

  • DD and E are often treated as equivalent; confirm with each brand.
  • Boutiques may relabel UK imports to US letters—always check tags.

Europe (EU / Continental sizing)

Band labels use centimetres (e.g., 70, 75). Cup steps usually follow single letters (A, B, C…) but vary by country (e.g., DE, ES).

  • Divide your bust measurement in cm by 2.54 to sanity-check conversions.
  • Some EU charts skip double letters—map via calculator and brand tables.

France/Spain (FR/ES)

Band adds 15 to the EU size (EU 75 → FR 90). Cups mirror EU letters.

  • Subtract 15 from FR label to get EU index, then convert to UK/US.
  • Double-check FR labels on vintage or luxury lingerie; patterns may differ.

Australia/New Zealand (AU/NZ)

Band equals UK band + 2 (UK 32 → AU 10). Cups mostly follow UK grading.

  • Sister sizes align closely with UK—convert band, then keep cup letters.
  • Sports bras may use alpha sizing; verify with impact planners.

Japan (JP)

Band uses centimetres (bust - underbust gives cup depth). Cups use letter plus number increments (A65, B70).

  • Cup increments are smaller; expect to size up if converting from UK/US.
  • Use official charts for brands like Wacoal Japan to avoid rounding errors.

Pre-flight conversion checklist

  • Run the calculator using your current measurements in inches and centimetres; record both.
  • Note your sister sizes so you can pivot when bands are sold out or run tight by region.
  • Download relevant brand conversion tables before you checkout carts (Triumph, Elomi, Nike, etc.).
  • Check retailer return policies for international orders and whether they accept EU vs UK labels.
  • Log every international order in the measurement log template, noting deviations from expected fits.

Conversion tools & downloads

Mix and match these resources as you plan your next international haul or cross-border fitting.

Measurement log template (PDF)Triumph global conversion chartVictoria’s Secret US ↔ international guideSee who benefits from conversions

Frequently asked questions

How do I convert a UK 34F to EU and US sizes?

Start with the calculator baseline. A UK 34F converts to EU 75G (band 34 → 75; cup F → G) and typically US 34G. Confirm with brand tables because US designers may label F and G differently.

What if a brand mixes alpha (XS–3X) and traditional sizing?

Use the calculator to get your band/cup, then find the alpha equivalent via the brand’s chart (e.g., Nike Alpha Medium ≈ 34D/36C). Log the alpha size alongside traditional sizes for easy reference.

Do I need new measurements for every conversion?

No, but you should re-measure if your body changes. Store your underbust and bust in both inches and centimetres so you can convert quickly without re-measuring.