US to UK shoe size converter

The complete US to UK shoe size guide: formulas, widths, and brand notes

Shoppers purchasing footwear from British retailers like Clarks, ASOS, and End Clothing must convert American sizes accurately. Both the American and British sizing systems share the imperial unit of the barleycorn, but an initial offset requires separate calculations for men and women.

1. Shared barleycorn heritage and scale offsets

Both the United States and the United Kingdom base their shoe sizing on the barleycorn, an imperial unit of one-third of an inch (8.46 millimeters). A half-size step represents one-sixth of an inch (4.23 mm). Full details on imperial footwear units appear in our shoe size in inches guide.

American and British sizes differ because their scales start from different baseline points. In the nineteenth century, American manufacturers set their baseline size 1 at 3 11/12 inches, while British lasts started at 4 inches. This produces a consistent half-size offset in men's footwear and a two-size offset in women's footwear.

2. Converting American men's sizes to British footwear (UK = US − 0.5)

For men, convert US shoe size to UK by subtracting 0.5 from the American size:

• US 7 converts to UK 6.5 (25.0 cm foot length).
• US 7.5 converts to UK 7.0 (25.5 cm foot length).
• US 8 converts to UK 7.5 (26.0 cm foot length).
• US 8.5 converts to UK 8.0 (26.5 cm foot length).
• US 9 converts to UK 8.5 (27.0 cm foot length).
• US 9.5 converts to UK 9.0 (27.5 cm foot length).
• US 10 converts to UK 9.5 (28.0 cm foot length).
• US 10.5 converts to UK 10.0 (28.5 cm foot length).
• US 11 converts to UK 10.5 (29.0 cm foot length).

An American men's size 8 corresponds to UK 7.5 and EU 41.

3. Converting American women's sizes to British footwear (UK = US − 2)

In women's footwear, the American scale starts three sizes ahead of men's sizing, while British women's sizing shares the same baseline scale as British men's sizing. To convert, subtract two full sizes:

• US 5 converts to UK 3.0 (22.0 cm).
• US 6 converts to UK 4.0 (23.0 cm).
• US 7 converts to UK 5.0 (24.0 cm).
• US 8 converts to UK 6.0 (25.0 cm).
• US 9 converts to UK 7.0 (26.0 cm).

This two-size reduction ensures proper heel-to-ball proportion in women's pumps, loafers, and boots.

4. Width standards between American and British lasts

Shoe fit depends on foot width as well as length. American and British manufacturers label widths with different letter codes:

• In men's shoes, standard American medium is D, narrow is B or C, and wide is E or 2E. In the UK, medium is F, wide is G, and extra wide is H.
• In women's shoes, standard American medium is B, narrow is 2A, and wide is D. In the UK, standard is D, and wide is E or EEE.

Shoppers with broad feet buying Goodyear-welted British shoes from Church's, Tricker's, or Loake should choose a British G fitting to ensure forefoot room.

5. Brand conversion notes for athletic and dress shoes

Major athletic brands follow specific internal conversion charts printed on shoe tongues:

• Nike applies a 1-size offset for men: US 10 corresponds to UK 9 and EU 44 for a 28.0 cm foot length. For women, Nike applies a 2.5-size offset: US 8 corresponds to UK 5.5 and EU 39 for a 25.0 cm foot length.
• Adidas uses one-third fractional increments: for men, US 9 translates to UK 8.5 and EU 42 2/3.
• Clarks and Dr. Martens build shoes on British lasts and convert to US by adding 0.5 for men and 2 for women.

To verify your physical foot length before ordering, measure your feet following our shoe size by foot length guide.