Clothing and shoe sizes use different standards by country/region and are not unified. Here's an explanation of major standards.
Clothing Size Standards
Japan uses numeric notation (S/M/L, size 7/9/11), US uses numbers and letters (0/2/4, XS/S/M/L), Europe uses numbers (42/44/46/48), UK uses unique numbers (6/8/10/12). Same body type = different sizes by country.
Shoe Size Standards
Japan uses centimeters (cm), US/UK use inch-based unique values, Europe uses Paris Points (2/3cm units), China uses millimeters (mm). Example: Japan 25cm = US 7 = UK 6 = EU 39.
Men's vs Women's Differences
Shoe sizes especially differ greatly by gender. In US shoe sizes, same foot length: men's 8 = women's 9.5. Clothing sizes also have different baselines by gender, so always specify gender for conversion.
Brand Variations
Even within same country standards, actual measurements vary by brand ("brand sizing"). Especially luxury brands (Gucci, Prada, etc.) and fast fashion (H&M, ZARA, etc.) have unique sizing. This tool is based on general standard sizes.
Ring Size Standards
Japan uses ring numbers (1-30), US uses numbers (3-15), UK uses letters (A-Z), Europe uses inner diameter in millimeters (mm). Example: Japan 11 = US 6 = UK L = EU 51mm.
Children's Clothing & Shoe Sizes
Kids' sizes are complex, based on age/height or foot length. For shoes, 0.5-1cm larger is typical considering growth. This tool supports standard kids' shoe sizes (13cm-24cm).
Unisex & One-Size Products
Hats, belts, gloves, etc. are often unisex or one-size-fits-all with less need for conversion. However, some items like international brand hats (inch notation) may require conversion.
Size Conversion Notes
This tool is based on general standard size charts, but actual products may vary by brand/product. Always check product page size charts before purchasing. For online shopping, also verify return policies for peace of mind.