Bra Size Converter

US · UK · EU · France · Australia · India

Convert bra sizes between US, UK, EU, French, Australian and Indian sizing systems instantly. Enter your band size and cup size, select your current system, and see all equivalent sizes at once.

US 34B = UK 34B = EU 75B | EU band = US band + 16 (approx) | 34C + 36B = sister sizes

About International Bra Sizing

Bra sizing is one of the most inconsistent measurement systems in global retail. Unlike clothing sizes, which have some loose international standardisation, bra sizes vary significantly between countries — not just in the numbers used, but in how band size is measured (inches vs centimetres), how cup letters are assigned, and how the fit model differs between brands. Understanding how your size translates across US, UK, EU and Australian standards is essential for online shopping, international travel or buying from foreign brands.

📏 Band Size — Inches vs Centimetres

US and UK band sizes are in inches, measured directly from the underbust circumference (rounded to the nearest even number). EU band sizes are in centimetres — you add approximately 16 to the US/UK band to get the EU equivalent (e.g. US 34 = EU 75, where 34 inches ≈ 86 cm, rounded down to the nearest EU standard of 75). French band sizes are yet another standard, adding more to the EU value. Australian bra band sizing has historically used the same inch scale as US/UK, though this varies by brand.

🔤 Cup Letters — Where They Diverge

For small to medium cups (AA through D), US, UK and EU cup letters are largely equivalent. The divergence happens above D: US uses DD, DDD; UK uses DD, E, F, FF; EU uses E, F, G. This means a US DDD = UK E = EU F — different letters, same cup volume. When shopping internationally, always use a size converter and check the brand's own size chart rather than relying on the letter alone. Indian bra sizing follows UK standards for cup letters but sometimes uses different band numbering by brand.

How to measure your bra size at home: Use a soft tape measure. (1) Band size: wrap the tape snugly around your ribcage just under your bust. Round to the nearest even number — this is your band size in inches. (2) Bust size: measure around the fullest point of your chest. (3) Cup size = bust − band. Each inch = one cup size: 1"=A, 2"=B, 3"=C, 4"=D, 5"=DD, 6"=DDD. For example: band 34", bust 36" → difference 2" → size 34B.

International Bra Size Chart

Common bra size equivalents across US, UK, EU and Australian sizing systems.

USUKEUFranceAustralia (approx)
32A32A70A85A10A
34A34A75A90A12A
34B34B75B90B12B
34C34C75C90C12C
34D34D75D90D12D
34DD34DD75E90E12DD
34DDD34E75F90F12E
36B36B80B95B14B
36C36C80C95C14C
36D36D80D95D14D
38C38C85C100C16C
38D38D85D100D16D

Common Bra Size Conversions

US 34B → All systems
= UK 34B = EU 75B = French 90B
US 36C → All systems
= UK 36C = EU 80C = French 95C
US 34D → All systems
= UK 34D = EU 75D = French 90D
US 36D → All systems
= UK 36D = EU 80D = French 95D
US 38C → All systems
= UK 38C = EU 85C = French 100C
US 34DD → All systems
= UK 34DD = EU 75E = French 90E

Worked Examples

Measuring Your Size
Band: 34" underbust
Bust: 37"
37 − 34 = 3" → C cup
→ Size 34C
A woman measuring 34" around her ribcage and 37" at the fullest point of her bust has a 3-inch difference = C cup. Her US/UK size is 34C = EU 75C = French 90C = Australian 12C.
Shopping from a UK Brand
US size: 34DD
UK equivalent: 34DD (same)
Cup letters match at DD
A US shopper buying from a UK brand in size 34DD can order the same size — US and UK use identical band sizes and the same DD cup label. Divergence begins at DDD: US DDD = UK E. Always check the brand's own chart for sizes above DD.
Shopping from a European Brand
US size: 34B
EU band: 34 + ~41 = 75
EU cup: B (same letter)
→ EU 75B
Converting US 34B to EU: the band becomes 75 (EU uses underbust in cm, standardised to nearest 5). The B cup letter is the same in both systems. So order EU 75B from a European lingerie brand.
Sister Sizing
34C sister sizes:
32D (tighter band)
36B (looser band)
If 34C is sold out, try a sister size. 32D has the same cup volume with a tighter band. 36B has the same cup volume with a looser band. Sister sizes share the same diagonal measurement from the back hook to the cup — only the band tension changes.

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People Also Ask — Bra Sizes

How do I measure my bra size at home?
Measure your underbust (band size) in inches — round to nearest even number. Measure your bust at the fullest point. Subtract band from bust: 1"=A, 2"=B, 3"=C, 4"=D, 5"=DD. Example: 34" band + 36" bust = 2" difference = 34B.
What is US 34B in UK and EU?
US 34B = UK 34B (identical) = EU 75B (band +41 cm approximately). Band and cup are the same letter in US and UK up to D. EU uses the same cup letters but higher band numbers based on centimetre measurements.
What are sister sizes in bras?
Sister sizes have the same cup volume but different band sizes. To go up one band, go down one cup: 34C → 36B. To go down one band, go up one cup: 34C → 32D. All three are sister sizes — same cup volume, different band tension. Useful when your exact size is out of stock.
Why is US DDD different from UK DDD?
US DDD = UK E = EU F. US sizing uses DD, DDD, DDDD after D. UK sizing switches to E, F, FF, G after DD. The cup volumes are the same — only the letter names differ. This is the most common source of confusion when buying bras internationally.
What is the most common bra size?
The most commonly sold size in the US is around 34DD by modern fitting standards (older data cited 34B, but fitting research has revised this). In the UK, 36D is commonly cited. In India, 34B is most common. Note: studies consistently show most women wear an incorrect size.
How do Australian bra sizes compare to US?
Australian bra bands have historically used dress-size numbering (10, 12, 14, 16) rather than inches. US 32 ≈ AU 10, US 34 ≈ AU 12, US 36 ≈ AU 14, US 38 ≈ AU 16. Cup letters follow UK conventions (AA, A, B, C, D, DD, E, F). However, many Australian brands now use the US/UK inch-based system directly.

Who Uses a Bra Size Converter?

🛍️
Online Shoppers
Buying from international lingerie brands — French labels like Simone Pérèle, UK brands like Freya or Fantasie, or European designers — requires converting your size to their system before adding to cart.
✈️
Travellers & Expats
Shopping for lingerie while abroad or relocating to a country with a different sizing system means your usual "34B" won't map directly. A converter ensures you pick the right size in the local numbering system.
🎁
Gift Buyers
Buying lingerie as a gift from an international brand requires converting the recipient's size. A converter helps ensure the right fit without needing to ask embarrassing questions about exact measurements.
👗
Fashion & Wardrobe Professionals
Stylists, wardrobe assistants and costume designers working with talent from multiple countries regularly need to convert between US, UK and EU sizes when sourcing garments internationally.
📦
E-commerce Sellers
Online lingerie retailers selling internationally need accurate size conversion charts to serve customers in multiple countries. This converter helps both buyers and sellers understand cross-market sizing equivalents.
👩‍💻
New to Bra Shopping
First-time bra shoppers or those transitioning from one country's sizing to another use converters to understand how their measurements translate into standard size labels across different systems.

Bra Sizing Tips

EU Band

To convert US/UK band to EU: add approximately 16 to the US inch value, then round to the nearest 5 (e.g. 34+16=50, nearest EU standard is 75, because EU measures the full underbust in cm ≈ 86, rounded to 85/75 depending on the brand's standard). Always verify with the specific brand's chart.

Cup Above D

Never assume the cup letter is the same above D across systems. US DD = UK DD = EU E. US DDD = UK E = EU F. US G = UK G = EU H (approximately). When in doubt, use the cup volume equivalence rather than the letter name. Most European brand size charts include a full conversion table.

Sister Size

If your size is unavailable, try going up one band / down one cup (same volume, looser fit) or down one band / up one cup (same volume, tighter fit). This is particularly useful for online purchases where your exact size sells out — sister sizes share the same underwire width.

Frequently Asked Questions — Bra Size Converter

Use a soft measuring tape. Step 1: Measure your band size by wrapping the tape snugly around your ribcage directly under your bust. Round to the nearest even number. Step 2: Measure your bust size at the fullest point of your chest. Step 3: Subtract band from bust — each inch difference equals one cup size: 1"=A, 2"=B, 3"=C, 4"=D, 5"=DD, 6"=DDD.
US 34B = UK 34B (identical band and cup) = EU 75B (band number is higher because EU uses centimetre-based sizing) = French 90B. Cup letters are equivalent for B cups across all systems. The divergence primarily happens at DD and above.
EU band sizes reflect the underbust circumference in centimetres, rounded to the nearest standard value. A US 34" band = approximately 86 cm underbust, which rounds to EU 85 or 75 depending on the brand's standard. Adding roughly 16 to the US inch value gives a good approximation of the EU band number.
Sister sizes are bra sizes that have the same cup volume but different band sizes. Going up one band size and down one cup gives the same cup volume (e.g. 34C and 36B). Going down one band and up one cup also maintains volume (34C and 32D). Sister sizing is useful when your exact size is unavailable.
Australian bra band sizes have historically used dress sizes (10, 12, 14, 16) rather than inches. US 34 ≈ AU 12, US 36 ≈ AU 14. Cup letters follow UK conventions. However, many Australian brands now use the US/UK inch-based system directly, so always check the brand's specific chart.
DD (double D) in US and UK sizing represents a 5-inch difference between bust and band. In European sizing this is called E. US DD = UK DD = EU E. Above DD: US DDD = UK E = EU F. This naming divergence is why bra size conversion is necessary when shopping internationally.
Studies suggest the most commonly sold size in the US is around 34DD by modern fitting standards. In the UK, 36D is commonly cited. In India, 34B is most common. Sizes vary significantly by country. Note: fitting experts consistently find that most women wear an incorrect bra size — professional fitting is recommended.

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