UK Shoe Sizes Explained
British shoe sizes share the same barleycorn heritage as US sizes, but start at a different point on the scale — so a UK 8 and a US 8 are not the same foot length. Here is what you need to know.
What it is
UK sizing is based on the barleycorn, the same one-third-of-an-inch unit that underlies US sizing. One whole UK size equals one barleycorn (roughly 8.5 mm) of additional foot length; half sizes add half a barleycorn.
The UK scale and the US scale share the same step size but have different starting points — different "zero" offsets — which is why a UK 9 and a US 9 correspond to different foot lengths.
Where it is used
UK sizing is standard across the United Kingdom and Ireland, and is the traditional reference in many Commonwealth countries. International brands that originate in the UK typically use UK sizes as their primary scale.
How the numbers work
For men's footwear, UK sizes run approximately one whole size below the equivalent US size for the same foot. A man with a UK 8 foot wears a US 9 (same physical length). The relationship is consistent across the range: UK = US − 1 for men's.
For women's footwear, the offset is larger: UK sizes run approximately two sizes below the equivalent US size for the same foot. A woman with a UK 6 foot wears a US 8.
Like US sizes, UK sizing has no universal standard enforced across brands — the numbers are customary rather than legally defined. Some makers may be half a size off from others.
Men's, women's and children's
Men's and women's UK sizes use separate scales with different offsets from physical foot length. Children's UK sizes are widely used in British retail and follow their own progression from small infant sizes up through youth.
When comparing across genders (for example, shopping for unisex footwear), always convert through foot length in cm or inches rather than assuming a fixed offset between men's and women's scales.
Tips for buying
Always check whether a product specifies UK or US sizing — the label "size 8" means different foot lengths in each system. Many international retailers list both.
If you know your US size, subtract 1 for men's (or 2 for women's) to get the approximate UK equivalent. The diagram below shows exact foot-length values for each UK size.
As with all size systems, conversion is approximate. Always try footwear if possible, or measure your foot and cross-reference with the maker's specific chart.
Men's size chart: UK, US/CA, EU, Japan/Mexico, China, inches, cm
| UK | US/CA | EU | Japan/Mexico | China | Inches | CM |
|---|---|---|---|---|---|---|
| 5 | 6 | 38 | 23.5 | 37 | 9.3 | 23.7 |
| 6 | 7 | 39 | 24.5 | 39 | 9.7 | 24.6 |
| 7 | 8 | 40 | 25.5 | 41 | 10 | 25.4 |
| 8 | 9 | 41 | 26 | 42 | 10.3 | 26.2 |
| 9 | 10 | 43 | 27 | 44 | 10.7 | 27.1 |
| 10 | 11 | 44 | 28 | 46 | 11 | 27.9 |
| 11 | 12 | 45 | 29 | 48 | 11.3 | 28.8 |
| 12 | 13 | 46 | 29.5 | 49 | 11.7 | 29.6 |
| 13 | 14 | 48 | 30.5 | 51 | 12 | 30.5 |
FAQ
Are UK shoe sizes unisex?
The UK numbering scale itself is unisex — the same sequence of numbers is used for men's and women's ranges — but men's and women's shoes are offset differently from foot length, so a men's UK 8 and a women's UK 8 are not the same foot length. Always check which range (men's or women's) a size is listed under.
How does UK children's sizing work?
UK children's sizes start from small infant sizes and run up through youth sizes before switching to the adult UK 1 range at around age 12–13. Children's UK sizes are one of the most widely used scales in British retail, including for school shoes.