Bra Size Converter & International Chart
Seamlessly convert your bra size between US, UK, EU, and French standards. Our expert tool ensures a perfect fit when shopping for international brands.
Select a size to see international equivalents
Introduction
In our globalized world, the lack of a universal bra sizing standard can make shopping across borders a frustrating experience. A 34D in the US may find herself needing a 75D in Germany or a 90D in France. Our Bra Size Converter demystifies these regional variations. Sizing systems are rooted in historical units and varying philosophies of fit. By providing a mathematical bridge between these systems, we help you navigate Italian luxury houses and French boutiques with confidence. Whether shopping online or planning a trip abroad, this tool ensures you always speak the language of fit. Understanding these nuances is the first step toward a globalized wardrobe that prioritizes both style and comfort.
Global Confidence, Local Fit
Sizing is a language. Learning to translate between systems opens up a world of designer lingerie and heritage brands that were previously inaccessible.
Accurate conversion prevents the 'Regional Fit Gap,' where consumers believe a brand 'runs small' when they are simply using the wrong system equivalent.
Understanding international standards allows you to shop the best of global craftsmanship, from British support to French elegance.
Knowledge of cup progressions ensures you maintain the correct volume and support levels, regardless of which alphabet the brand uses.
How to Use This Tool
Using the converter is simple and instant. First, select your 'Base Region'—the system you are most comfortable with (typically where you currently live). Next, input your current 'Band Size' (e.g., 34) and 'Cup Size' (e.g., D). The calculator will automatically generate the equivalent sizes for the other three major regions. For the 'European (EU)' and 'French (FR)' results, we use a conversion that accounts for the metric system (centimeters vs. inches). For 'UK' conversions, pay close attention to the cup letters; the UK system uses double letters (DD, E, F, FF) differently than the US system (DD, DDD, G). We recommend using your US or UK size as the most reliable anchor when converting to European standards, as the band tension in metric systems is often graded more precisely. Once you have your results, we provide a 'Sister Size' recommendation to help you adjust for brands that are known to run tight or loose in the band.
How the Calculation Works
Our conversion engine uses a three-tier mapping logic that addresses both band and cup variations. For band sizes, we use a direct translation table: US/UK 30 = EU 65, 32 = 70, 34 = 75, and so on. The French system adds 15 to the EU band (e.g., EU 75 = FR 90), reflecting a different historical measurement base. Cup conversion is more complex due to the varying progressions. We use a 'Volume-Equivalent Mapping' that aligns the physical depth of the cup across systems. For example, the US system often skips the E cup, going straight from DD to DDD, whereas the UK system uses E and F as distinct steps. Our logic aligns these by their cubic volume in cubic centimeters. The formula `BandEU = (BandUS - 32) * 2.5 + 70` provides a rough linear guide, but we use a hard-coded look-up table for 100% accuracy to ensure that the subtle grading differences in larger cup sizes are correctly represented.
Understanding Your Results
International sizes are a baseline. Use your converted size as the starting point when exploring the unique fit of brands from around the world.
Expert Pro Tips
Look for the 'UK' size on the tag of high-end bras. Even if you're in the US, the UK size is often the most accurate representation of the garment's true engineering and volume.
Remember that 2.54cm equals 1 inch. If you're stuck without a converter, you can do a rough band calculation by multiplying your US band by 2.5 and rounding to the nearest 5 (e.g., 34 * 2.5 = 85).
Don't ignore the 'FF' and 'GG' cups. If you are shopping UK brands and you see double letters after D, it's a sign of a high-quality, high-precision sizing system. Don't be afraid of the 'double letters'!
Check the brand's 'Home Country.' A brand founded in France (like Simone Pérèle) will always fit best if you use their native French sizing as your primary reference point.
Keep a digital note of your sizes in different systems. Having your US, UK, and EU sizes saved in your phone makes international online shopping much faster and reduces the risk of expensive returns.
Glossary
Band Size
The numerical part of a bra size, representing the circumference of the ribcage; measured in inches in the US/UK and centimeters in the EU.
Cup Progression
The sequence of letters used to denote increasing cup volumes; different countries use different sequences (e.g., US: DD, DDD vs. UK: DD, E, F).
Metric System
The decimal system of measurement (meters, centimeters) used by almost all countries outside the US for garment sizing.
Imperial System
The system of measurement based on inches and feet used for bra sizing in the United States and historically in the UK.
Volume-Equivalent
A method of sizing where the physical space inside the cup is matched between systems, even if the label letters are different.
Frequently Asked Questions
Why does the UK have different cup letters than the US?
Is a French 90D the same as a US 34D?
Should I always trust the conversion on the tag?
Does Asian sizing differ from European sizing?
What is the best way to convert my size for a sports bra?
Methodology & Transparency
While our conversions are technically accurate, individual brand 'scaling' (how they grade between sizes) can create variations. Always check the specific brand's fit notes.
The conversion logic is based on the ISO 8559-2:2017 garment construction standards and the 'Best Practice' mapping used by international multi-brand luxury retailers.