Comparison
US vs EU shoe size: why every conversion table disagrees
A 42 EU is not a 9 US. Sometimes it's a 9, sometimes 8.5, sometimes 9.5 — depending on the brand. Here's why.
Shoe sizing across regions is a mess. EU sizes use the Paris point (about ⅔ cm). US sizes use the barleycorn (⅓ inch). The UK uses a similar barleycorn system offset from the US one. And none of these systems measure the foot — they measure the last, the wooden form the shoe is built around, which varies between manufacturers. That’s why a 9 US in Nike doesn’t fit the same as a 9 US in Adidas.
The actual definitions
| System | Unit | Starting point | Increment |
|---|---|---|---|
| EU (Paris point) | ~6.67 mm | Size 0 = 0 mm last | 1 full size per increment |
| US (barleycorn) | ~8.47 mm | Size 1 child = ~3.94 in (100 mm) last | ½ size per ⅓ barleycorn |
| UK (barleycorn) | ~8.47 mm | Offset 0.5-1 size from US | ½ size per ⅓ barleycorn |
| Mondopoint (ISO 9407) | 1 mm | Direct foot length in mm | 5 mm or 7.5 mm increments |
Why the brand matters more than the conversion table
Last shape varies between brands. Nike’s lasts are relatively narrow; New Balance offers width grades; Italian dress shoes (Allen Edmonds, Salvatore Ferragamo) often run narrow in standard widths. Two shoes labelled “9 US” from different brands can differ by 5-10 mm in actual interior length, plus differences in toe-box volume, instep, and heel cup.
For online ordering, the most reliable workflow:
- Measure your foot in mm (heel to longest toe).
- Find the brand’s own size chart that maps EU/US to that mm length.
- Use that specific brand’s mapping, not a generic conversion.
The Mondopoint shortcut
Mondopoint (ISO 9407) is the only system that measures the actual foot in millimetres. Military boots, skiing, and skating use it. Athletic brands print Mondopoint on the box next to the EU/US size. If you know your foot length in mm, you can look up the Mondopoint number and bypass the conversion uncertainty entirely.
Typical adult Mondopoint values: 240 mm (US men’s 7), 260 mm (US 9), 280 mm (US 11), 300 mm (US 13).
A practical conversion table
The numbers below are accurate for most athletic brands. Dress shoes typically run half a size larger than these suggest.
| EU | US (men) | US (women) | UK | Foot length (mm) |
|---|---|---|---|---|
| 39 | 6.5 | 8 | 6 | 245 |
| 40 | 7 | 8.5 | 6.5 | 250 |
| 41 | 8 | 9.5 | 7.5 | 260 |
| 42 | 9 | 10.5 | 8.5 | 265 |
| 43 | 10 | 11.5 | 9.5 | 275 |
| 44 | 10.5 | 12 | 10 | 280 |
| 45 | 11.5 | — | 11 | 290 |
| 46 | 12 | — | 11.5 | 295 |
The men’s/women’s offset
US men’s sizes are 1.5 numbers lower than US women’s for the same physical shoe. A US men’s 8 is a US women’s 9.5. EU and Mondopoint don’t encode this offset — they’re unisex. UK uses one numbering across genders. The split is purely a US retailing convention.
Calculator
Convert any direction with our shoe size converter, which uses the standard barleycorn/Paris-point math (not a brand-specific chart).
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Published May 16, 2026