How to Convert US Shoe Sizes to UK
US and UK shoe sizes use the same unit of measurement (the barleycorn, equal to one-third of an inch per size step), but they start counting from different points. This results in a consistent offset between the two systems that varies depending on whether you are converting men's, women's or children's sizes.
The Conversion Formula
| Category | Formula | Example |
|---|
| Men's | UK = US − 0.5 | US 10 = UK 9.5 |
| Women's | UK = US − 2 | US 8 = UK 6 |
| Kids' (children's) | UK = US − 0.5 | US 4 = UK 3.5 |
These formulas apply to the standard sizing conventions used by most international footwear brands. Note that some brands may vary slightly from this standard, so always check the brand's own size guide when ordering online.
Why Are US and UK Shoe Sizes Different for Women?
The two-size gap between US and UK women's sizes reflects historical differences in how each country defined their women's sizing systems. In the US, women's sizing runs approximately two sizes higher than UK sizing for the same foot length. This convention has been maintained across the industry even as sizing has been standardised in other respects.
For men, the gap is just half a size. This smaller difference also has historical origins in how the respective sizing scales were set up in the 19th and early 20th centuries.
EU and Mondopoint Sizes
EU shoe sizes are based on the Paris Point system, where one size equals two-thirds of a centimetre in foot length. EU sizing is gender-neutral, so a EU 42 is the same foot length regardless of whether the shoe is men's or women's. The converter on this page shows approximate EU equivalents calculated from the foot length.
Mondopoint is an international standard that measures foot length directly in millimetres. Although it is used in some military and safety footwear contexts, it is rarely seen on consumer footwear in New Zealand or the UK.
Worked Example
Starting with a US men's size 10, the conversions work out as follows:
- UK: 10 − 0.5 = 9.5
- EU: UK 9.5 + 34.5 = 44
- Foot length (Paris point): EU 44 × 2/3 = approximately 29.3 cm
This matches the default output of the calculator above when Gender is set to Men's and US size is 10.
Tips for Buying Shoes Online
- Measure your foot length in centimetres for the most reliable size guidance.
- Foot width varies between brands; a converted size does not guarantee fit across different brands.
- Many NZ and Australian retailers list both US and UK sizes. If only one is given, use this converter to find the other.
- Half sizes are common in US and UK sizing. If your converted size falls between standard sizes, go up to the next half size for comfort.
- Children's shoe sizes in the US and UK use a separate scale that restarts at 1 after the toddler range ends. The formula UK = US − 0.5 applies across the children's range.
Related Converters
Method: Conversions use the standard offset formulas (Men's: UK = US − 0.5; Women's: UK = US − 2; Kids': UK = US − 0.5) consistent with international footwear industry conventions. EU equivalents are derived from foot length in centimetres using the Paris Point system (EU size = foot length in cm / 0.667). Foot length approximations use the standard barleycorn-based formula for UK/US sizing.
This converter provides standard size equivalents based on widely accepted industry conventions. Actual fit can vary between brands and styles. Always check the specific brand's size guide when ordering online, and where possible measure your foot length for the most accurate guidance.
