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United States sizes
Barleycorn (shoes) · Inch-based (clothing)
Numeric shoe sizes based on 1/3 inch increments, letter and numeric clothing sizes that drift over time.
Shoe size step
1/3 inch (8.47 mm)
Women's clothing
0, 2, 4, 6, 8, 10, 12...
Men's shirt
Chest in inches (36, 38, 40)
Men's trouser
Waist × Inseam (32 × 32)
US shoe sizing descends from the medieval English Barleycorn system. Each full size equals 1/3 of an inch (8.47 mm); half sizes are 1/6 inch. Men's, women's and kids' scales are offset from each other — a women's US 9 is a men's US 7.5 in the same shoe.
US clothing sizes for women are even numbers (0-20) nominally tied to bust/waist/hip measurements, but the actual measurements have crept larger over the past forty years (vanity sizing). Men's uses chest inches for tops and waist × inseam for trousers.
Common pitfalls
- Vanity sizing: a US 8 today measures wider than a US 8 from 1995.
- Women's/men's shoe offset is 1.5 US sizes — mismatch this and unisex shoes fit wrong.
- Kids' sizes flip from 'C' (child) to 'Y' (youth) at US 1Y, then join adult sizing.
Calculators
Brand guides for United States
Related articles
US Clothing Sizes Explained
Why US clothing sizes have drifted, how numeric and letter sizes relate, and what a US Medium actually means abroad.
US vs EU Shoe Sizes Explained
US and EU shoe sizes measure different things on different scales. Here's exactly how they convert and where the systems disagree.
Men's vs Women's Shoe Sizes
The difference is 1.5 US sizes — but the shoes themselves aren't identical. Here's what changes when a shoe is labeled for men or women.