General
Shoe Size Conversion Calculator
Convert shoe sizes between different international sizing systems including US, UK, EU, and more.
Reviewed by the calculator.uk.com Team · Last reviewed 1 May 2026 · Our methodology
Enter a shoe size and select conversion systems to see the result
Related to Shoe Size Conversion Calculator
The Shoe Size Conversion Calculator helps you convert shoe sizes between different international sizing systems, including US, UK, and EU standards. The calculator uses standardized conversion formulas based on established sizing relationships between these systems. Each sizing system has its own unique scale and starting point, which our calculator takes into account to provide accurate conversions.
Key Conversion Relationships
• US to UK: Subtract 0.5 from US size
• US to EU: Add 33 to US size
• UK to EU: Add 33.5 to UK size
These conversions are based on standard adult shoe sizing. It's important to note that while these conversions are generally accurate, there can be slight variations between different shoe manufacturers and styles. The calculator provides a reliable starting point for size conversion, but we recommend trying shoes on whenever possible.
The calculator provides straightforward size conversions between your selected systems. The results show both the original size and the converted size, making it easy to understand the equivalent size in your target system. When interpreting the results, keep in mind that shoe sizes can sometimes vary by half sizes, which is why our calculator supports decimal values.
Size Variations
While the calculator provides precise mathematical conversions, actual shoe sizes may vary slightly between brands and styles. Use these conversions as a guide, and consider trying half a size up or down when purchasing shoes in a different sizing system.
1. Why do shoe sizes differ between countries?
Shoe sizes vary between countries due to historical development of different measurement systems. The US system is based on inches, the UK system on barleycorns (⅓ inch), and the EU system on centimeters, leading to different numerical scales.
2. Are men's and women's shoe sizes the same?
No, men's and women's shoe sizes typically differ. In the US system, women's sizes are generally about 1.5 to 2 sizes larger than men's sizes. This calculator focuses on one gender's sizing at a time for accuracy.
3. Why do some shoes fit differently even in the same size?
Shoe fit can vary due to differences in manufacturing processes, brand standards, shoe style, and materials used. Additionally, foot width and arch height can affect how a shoe fits, even when the length measurement is correct.
4. How accurate are online shoe size conversions?
Online shoe size conversions are generally accurate for standard sizing but should be used as a guide. Factors like brand variations, style differences, and individual foot characteristics can affect the actual fit. It's always best to try shoes on when possible.
5. What is the scientific source for this calculator?
Shoe sizing is one of the least standardized areas of measurement: there is no single global system, and the US, UK, EU, and other regional scales each developed independently, with the EU/European sizing based on the length of the shoe's last measured in units of two-thirds of a centimeter. The ISO has published the Mondopoint system (based directly on foot length and width in millimeters) as an attempt at international standardization, but it has seen limited adoption outside specialized markets like military and athletic footwear. Because brands vary their own lasts and fit, and mappings between regional scales are conventions rather than exact conversions, results here should be treated as a close approximation rather than a guarantee of fit.