US & Canadian Shoe Sizes Explained
US and Canadian shoes use the same numbering system, built on a centuries-old unit called the barleycorn — one-third of an inch. Once you understand this, the numbers start to make sense.
What it is
The US and Canadian sizing system is based on the barleycorn, a traditional English unit equal to one-third of an inch (approximately 8.5 mm). Each whole shoe size represents one barleycorn of additional foot length. Half sizes add half a barleycorn — one-sixth of an inch.
The scale has historical roots in a 14th-century English decree that defined shoe sizes in barleycorns. Modern US and Canadian sizing keeps this heritage intact, so the numbers are rooted in a physical unit even if most shoppers never think about it.
Where it is used
The US sizing system is standard across the United States and Canada. Because North American brands dominate global retail, US sizes appear on many products sold worldwide, so knowing your US size is useful even when shopping internationally.
How the numbers work
Each size step equals one-third of an inch of foot length. So a US men's size 9 corresponds to a foot roughly one barleycorn longer than a size 8. The numbers start from a historical baseline, not from zero, which is why small sizes begin in the single digits.
Men's and women's US sizes use separate scales for the same foot. A women's size 8 is typically about one and a half sizes larger than the men's number for the same physical foot length — meaning a woman with a size-8 foot and a man with a size 6.5 foot are the same length. This offset is a quirk of the system, not a sign of different fit.
Men's, women's and children's
Men's and women's sizes are separate scales. For the same foot length, a women's size runs about 1.5 higher than the corresponding men's size. This matters when shopping for unisex or gender-neutral footwear.
Children's sizes start from infancy and run up to around a US 7 (toddler/youth), at which point they overlap with adult sizes. There is a separate youth scale that eventually merges into the adult men's range.
Tips for buying
US and UK sizes are not the same. Men's US sizes run approximately one size above UK (US 9 ≈ UK 8). Women's US sizes run approximately two sizes above UK (US 8 ≈ UK 6). Always check which system a product uses.
The diagram and conversion table on this page show exact correspondences to foot length in cm and inches, which is the most reliable way to compare across systems. Sizes are approximate — brands and styles vary, and the same size from two makers may fit differently.
When in doubt, measure your foot and use the centimetres or inches values to find your equivalent in any system.
Men's size chart: US/CA, UK, EU, Japan/Mexico, China, inches, cm
| US/CA | UK | EU | Japan/Mexico | China | Inches | CM |
|---|---|---|---|---|---|---|
| 6 | 5 | 38 | 23.5 | 37 | 9.3 | 23.7 |
| 7 | 6 | 39 | 24.5 | 39 | 9.7 | 24.6 |
| 8 | 7 | 40 | 25.5 | 41 | 10 | 25.4 |
| 9 | 8 | 41 | 26 | 42 | 10.3 | 26.2 |
| 10 | 9 | 43 | 27 | 44 | 10.7 | 27.1 |
| 11 | 10 | 44 | 28 | 46 | 11 | 27.9 |
| 12 | 11 | 45 | 29 | 48 | 11.3 | 28.8 |
| 13 | 12 | 46 | 29.5 | 49 | 11.7 | 29.6 |
| 14 | 13 | 48 | 30.5 | 51 | 12 | 30.5 |
FAQ
Is Canadian shoe sizing the same as US sizing?
Yes. Canada and the US share an identical numbering system for men's, women's and children's footwear — a US 9 and a Canadian 9 are the same foot length, so no conversion is needed between the two.
What do the width letters (B, D, E, EE) mean on a US shoe box?
US shoe boxes often carry a width letter alongside the length size — B is narrow, D is standard/medium for men (B is standard for women), and E/EE/EEE indicate progressively wider fittings. The length conversion on this page gets you the right number; check the brand's width chart if you need a specific width.