Clothing Size Systems Explained
Why does a Medium at Zara feel different from a Medium at Nike? Here's how sizing systems work around the world — and why they don't always agree.
US Sizing: Letters and Numbers
The US uses two parallel systems: letter sizes (XS through XXXL) for casual wear and number sizes (0-22 for women, 28-44 for men's pants) for more formal clothing. There's no federal standard, so each brand defines what "Medium" means independently. This is why a size 8 at Gap differs from a size 8 at Zara.
Takeaway: US sizes are a starting point, not a guarantee. Always check the brand's size chart.
EU Sizing: Centimeter-Based Numbers
European sizes use body measurements in centimeters. Women's sizes range from 32 (XS) to 52+ (XXXL). The system is more logical than US sizing because the numbers relate to actual body measurements. For women, divide the EU size by 2 and add 6 to approximate the US number size.
Takeaway: EU sizing is more consistent across brands than US sizing.
UK Sizing: The 4-Number Offset
UK women's sizes run 4 numbers higher than US sizes (UK 12 = US 8). For men, UK and US sizes are identical — both use inches for chest and waist. The UK system is well-established and relatively consistent across British brands.
Takeaway: For women's clothes, subtract 4 from the UK size to get your US size.
Italian Sizing: EU Plus 4
Italian sizes run 4 numbers higher than standard EU sizes (Italian 42 = EU 38 = US 6-8). Italian brands like Gucci, Prada, and Versace use this system. French sizes are similar to Italian but can vary by 2 numbers.
Takeaway: Always check if a European brand uses standard EU or Italian sizing.
Asian Sizing: 1-2 Sizes Smaller
Clothing from Japanese, Korean, and Chinese brands typically runs 1-2 sizes smaller than Western equivalents. A "Large" in Asian sizing often fits like a US Medium. Some Asian brands use centimeter-based sizing that doesn't map to Western letter sizes at all.
Takeaway: Size up 1-2 sizes when buying from Asian brands or shopping on sites like Uniqlo, Shein, or Muji.
Vanity Sizing: Why Sizes Keep Changing
Over the past 50 years, US clothing sizes have gotten larger while keeping the same labels. What was a size 8 in 1970 is roughly a size 0 today. Brands do this to make customers feel better about their size — hence "vanity" sizing. This means vintage clothing runs much smaller than modern equivalents.
Takeaway: Never assume your size based on a label. Your measurements are the only reliable reference.
Find Your Size Across Systems
Use your measurements to find your exact size across US, EU, UK, and brand-specific charts.
Also see: How to measure yourself