International Size Charts Explained

With global e-commerce making it easier than ever to shop from any country, understanding international sizing systems has become essential. This guide explains how the major sizing systems work and why they differ.

Why Do Sizing Systems Differ?

Each country developed its sizing standards independently, often based on different measurement units (inches vs. centimeters), different starting points, and different measurement methods. There is no single universal standard, which is why a "size 42" means different things depending on whether you're looking at European shoes, Italian clothing, or Japanese outerwear.

Shoe Sizing Systems

US & Canada

The American shoe sizing system is based on the Brannock device, invented in 1927. It uses different scales for men, women, and children. Women's sizes are typically 1.5 sizes larger than men's for the same foot length (a women's 9 = men's 7.5). Sizes increase in increments of 1/3 inch.

European (EU)

European sizes use the Paris point system, where each size represents 2/3 of a centimeter (6.67mm). The system is unisex — the same number applies to both men and women. EU sizes typically range from 35 to 48 for adults.

United Kingdom

UK sizes are similar to US sizes but offset. UK men's sizes are approximately 0.5 to 1 size smaller than US men's sizes. UK women's sizes are approximately 2 sizes smaller than US women's sizes.

Japan (JP)

Japan uses the simplest system: foot length in centimeters. A JP 27 shoe is designed for a 27cm foot. This makes it the easiest system to measure for directly.

Clothing Sizing Systems

International (S/M/L)

The letter-based system (XS, S, M, L, XL, etc.) originated in the US and is now used globally as a simplified reference. However, what constitutes a "Medium" varies significantly between countries and brands.

US Clothing

US women's clothing uses even numbers (0, 2, 4, 6, 8, etc.) while US men's clothing uses chest/waist measurements in inches or letter sizes. US women's sizes have experienced "vanity sizing" — today's size 6 is notably larger than a size 6 from decades past.

European Clothing

European sizes are numeric and based on body measurements. Italian, French, and German systems all differ despite being "European." Italian sizes tend to be 4 sizes higher than US sizes, while French sizes are 2 sizes higher.

Ring Sizing Systems

Ring sizes vary widely between countries. The US uses a numeric scale, the UK uses letters (A through Z), Europe uses the inner circumference in millimeters, and Japan has its own numeric scale. Our ring size converter handles all these conversions.

Bra Sizing Systems

Bra sizes have two components: the band size (underbust measurement) and the cup size (difference between bust and underbust). Band sizes differ between systems — a US 34 band is equivalent to EU 75, FR 90, and UK 34. Cup letters also differ, particularly above a D cup where US, UK, and EU systems diverge significantly.

Tips for International Shopping

• Always check if a brand's size guide specifies which system they use
• Asian sizing (JP, KR, CN) tends to run smaller than Western sizing
• When in doubt, size up — it's easier to deal with slightly loose than too tight
• Read product reviews for fit-specific feedback from other international buyers
• Use our size converter to check before purchasing