International Shoe Size Conversion Guide - US, UK, EU

Reviewed: November 2025

Introduction

Shopping for shoes internationally can be confusing when faced with different sizing systems. A size 8 in the United States doesn't equal a size 8 in the UK or Europe. Understanding how to convert between US, UK, European, and Asian shoe sizes ensures you order the correct fit when shopping online from international retailers, traveling abroad, or buying gifts for someone in another country. This comprehensive guide demystifies shoe size conversion and helps you find the perfect fit every time.

Understanding Different Sizing Systems

Shoe sizing systems developed independently in different countries, leading to the confusing international landscape we have today. Each system uses different units of measurement and starting points. The United States and Canada use a system based on the barleycorn, an old English unit equal to one-third of an inch. The UK uses a similar barleycorn-based system but with a different zero point. European sizes use the Paris point, equal to 2/3 of a centimeter. Asian sizes typically measure foot length directly in centimeters or millimeters—similar to how different regions use different measurement standards as explained in our metric vs imperial systems guide.

These systems also differ in how they account for men's, women's, and children's sizes. In the US, women's sizes run approximately 1.5-2 sizes larger than men's for the same foot length. UK sizes use the same scale for men and women but start at different points. European sizes are generally unisex, with the same number indicating the same foot length regardless of gender, though manufacturers may cut shoes differently for men and women.

Adding to the complexity, different brands within the same country may size shoes slightly differently. Athletic shoe brands might run large or small compared to dress shoe manufacturers. Designer luxury brands sometimes use vanity sizing. This means conversion charts provide general guidance, but trying shoes on or checking brand-specific size charts is always recommended when possible. Foot shape also matters—width, arch height, and toe length all affect fit beyond simple length measurements.

US Sizing System

The United States shoe sizing system uses whole and half sizes, with men's sizes typically ranging from 6 to 16 and women's from 5 to 12. The system is based on foot length measured in barleycorns (1/3 inch increments). A men's size 1 corresponds to 8-1/3 inches (25 barleycorns), with each full size increasing by one barleycorn (1/3 inch). This means a men's size 10 is approximately 11-1/3 inches long.

Women's sizes in the US run approximately 1.5 sizes larger than men's for the same foot length. A women's size 8 is roughly equivalent to a men's size 6.5. This offset originated from historical conventions and persists today. Children's sizes in the US start at size 0 for infants (approximately 3-11/16 inches) and go up to around size 13.5, then switch to adult sizing. Youth sizes bridge the gap between children's and adult sizes.

Width measurements are also important in US sizing. Standard width is designated as B for women and D for men. Narrow widths are AA (women) or B (men), while wide widths are D (women) or EE/2E (men). Extra wide goes to EEE or 4E. Not all manufacturers offer multiple width options, but athletic shoe brands and comfort shoe makers typically do. Proper width fitting is crucial for comfort, especially for people with particularly narrow or wide feet.

UK Sizing System

The United Kingdom sizing system also uses barleycorns but with a different starting point than the US system. A UK size 1 (the smallest adult size) measures 8-1/3 inches, the same as a US men's size 1, but the UK uses this baseline for both men and women. UK sizes typically range from 3 to 13 for adults, with half sizes available. The progression is the same—each size represents 1/3 inch of length.

The key difference between UK and US sizing is the offset. UK sizes run approximately one size smaller than US men's sizes, meaning a US men's 10 equals roughly a UK 9. For women, UK sizes are about two sizes smaller than US women's sizes—a US women's 8 corresponds to approximately a UK 6. This can cause confusion when shopping from British retailers or brands like Dr. Martens, Clarks, or Church's that use UK sizing.

UK children's sizes follow a similar pattern, starting at size 0 for very young children and progressing through the numbers. Some UK brands distinguish between "child" sizes (roughly 10-13) and "junior" sizes (1-5.5) before transitioning to adult sizes. British shoe manufacturers are known for quality craftsmanship and traditional sizing standards, though like US brands, modern athletic and casual shoe makers may vary from these traditional standards.

European Sizing System

European shoe sizes, also called Continental or French sizes, use the Paris point system where each size equals 2/3 of a centimeter. European sizes typically range from about 35 to 48 for adults, with sizes progressing in whole numbers (though some manufacturers use half sizes). A European size 40 corresponds to a foot length of approximately 26.7 centimeters. The system is theoretically unisex, with the same size number indicating the same foot length for men and women.

Converting between US and European sizes requires accounting for the different measurement systems and gender conventions. A US men's size 10 is approximately EU size 43-44, while a US women's size 10 is approximately EU size 40-41. The European system's metric basis makes it more straightforward mathematically, but the lack of gender differentiation in the numbering can confuse shoppers accustomed to US or UK conventions.

Italian shoe sizing is closely related to European sizing but sometimes differs slightly. Italian brands may size shoes differently depending on style—dress shoes, sneakers, and boots from the same manufacturer might fit differently even in the same size. French and German brands generally adhere more strictly to standard European sizing. When buying Italian designer shoes, checking the specific brand's size guide is especially important due to these variations.

Asian Sizing Systems

Asian countries typically use foot length measurements in centimeters or millimeters for shoe sizing, making the system intuitive and precise. Japanese sizes, for example, directly measure foot length in centimeters. A size 25.5 indicates a foot length of 25.5 cm. This straightforward approach eliminates much of the confusion inherent in Western sizing systems. Korean and Chinese sizing systems work similarly, though specific scales may vary slightly between countries. For accurate foot length conversions, our length units guide provides detailed information.

Japanese sizes typically range from about 22 cm to 30 cm for adults. To convert from US sizes to Japanese, you generally measure your foot length in centimeters and add 0.5-1 cm for shoe comfort allowance. A US men's size 10 (approximately 28 cm foot length) would typically be a Japanese 28.5 or 29. Korean sizes work similarly but may use slightly different conversion offsets.

Chinese shoe sizing sometimes uses a different scale called the Mondopoint system, measuring foot length in millimeters. A size 260 indicates a 260mm (26 cm) foot length. Some Chinese manufacturers also use European sizing or create their own hybrid systems. When shopping from Asian retailers or brands, always check the specific size chart provided, as conventions can vary. Many Asian shoe brands assume narrower foot widths than Western brands, so people with wide feet may need to size up.

Men's Shoe Size Conversions

For men's shoes, here are common conversion reference points: US size 7 = UK 6 = EU 40 = 25 cm; US 8 = UK 7 = EU 41 = 26 cm; US 9 = UK 8 = EU 42-43 = 27 cm; US 10 = UK 9 = EU 43-44 = 28 cm; US 11 = UK 10 = EU 44-45 = 29 cm; US 12 = UK 11 = EU 45-46 = 30 cm. These are approximations, as exact conversions depend on manufacturer standards and how they account for toe room and shoe construction.

Athletic shoe brands like Nike, Adidas, and New Balance often provide their own conversion charts that may differ slightly from general conversions. Performance running shoes might be sized to accommodate foot swelling during exercise, suggesting sizing up half a size from your measured foot length. Dress shoes from luxury brands may run narrow and require careful attention to width measurements beyond simple length conversion.

When converting men's sizes, remember that the relationship between systems isn't perfectly linear due to different starting points and increments. Don't simply add or subtract a constant number across all sizes. Instead, use a reliable conversion chart or calculator, and when in doubt, measure your foot length in centimeters for the most accurate size determination. Many online retailers now provide tools to measure your foot using a smartphone camera for precise sizing.

Women's Shoe Size Conversions

Women's shoe conversions: US 6 = UK 4 = EU 36-37 = 23 cm; US 7 = UK 5 = EU 37-38 = 24 cm; US 8 = UK 6 = EU 38-39 = 25 cm; US 9 = UK 7 = EU 39-40 = 26 cm; US 10 = UK 8 = EU 40-41 = 27 cm; US 11 = UK 9 = EU 41-42 = 28 cm. Again, these are approximate conversions and actual sizing varies by brand and style. Women's shoe sizing shows more variation between brands than men's, making trying on or checking detailed size charts especially important.

Designer shoe brands often run small or use European sizing exclusively. Brands like Manolo Blahnik, Christian Louboutin, and Jimmy Choo typically use EU sizing and may fit narrower than mass-market brands. Many women find they need to size up half or even a full size in designer heels compared to their everyday sneaker size. Boot sizing can also differ from regular shoe sizing, with calf width and shaft height being additional considerations beyond foot length.

Women shopping for athletic or unisex shoes might encounter men's sizing. To convert from women's to men's US sizes, typically subtract 1.5-2 sizes. A women's 8 would be approximately a men's 6-6.5. This conversion is useful when a particular shoe style or colorway is only available in men's sizes, or when seeking wider options, as men's shoes are generally cut wider than women's.

Children's Shoe Sizing

Children's shoe sizing is more complex due to rapid growth and multiple age-based categories. US infant sizes (0-13) cover babies and toddlers, with size 0 being approximately 3.5-4 inches long. Toddler sizes (4-13) cover ages roughly 1-5 years. Youth sizes (1-7) bridge the gap to adult sizes. The progression isn't perfectly linear, and children's shoes should be checked frequently as feet can grow rapidly, sometimes requiring new shoes every few months.

UK children's sizes follow a similar structure with infant, child, and junior categories. European children's sizes typically range from 16 to 39, with smaller numbers for babies and toddlers. Asian children's sizes use centimeters like adult sizes. When buying children's shoes internationally, accurate foot measurement is crucial since growth stages don't align perfectly across different sizing systems. Allowing some growing room (about 1 cm) is standard practice, but too much extra space causes tripping and poor support.

Children's feet should be measured every 2-3 months for young children and every 4-6 months for older children. Proper fit is essential for healthy foot development—too-small shoes can cause deformities, while too-large shoes don't provide adequate support. Many children's shoe stores offer free foot measuring services, and buying shoes from retailers with easy return policies is wise given how quickly children outgrow footwear.

Width Measurements and Fit Considerations

Width is as important as length for proper fit. The US system designates widths with letters: for women, AA (extra narrow), A (narrow), B (medium/standard), C (wide), D (extra wide), and sometimes E or EE. For men, standard width is D, with B being narrow, 2E being wide, and 4E being extra wide. European and Asian sizing systems don't typically specify width, assuming a standard medium width, though some brands offer wide versions.

People with wide or narrow feet often struggle to find properly fitting shoes, as many brands only offer medium widths. New Balance, Brooks, and Asics are known for offering multiple width options in athletic shoes. Allen Edmonds and other premium dress shoe manufacturers provide width options for men's dress shoes. Trying shoes on is especially important for those needing non-standard widths, as sizing up in length to accommodate width leads to poor fit and foot problems.

Beyond length and width, other fit factors include arch height, toe box shape, and heel cup design. High arches require shoes with good arch support, while flat feet benefit from stability features. Some people have longer second toes (Morton's toe), requiring roomier toe boxes. Heel width varies—narrow heels may slip in standard shoes, while wide heels need secure heel cups. These individual variations mean shoe fit is never just about the size number on the box.

Practical Shopping Tips

Measure your feet regularly, as foot size can change with age, weight fluctuations, and pregnancy. Measure both feet, as they're often slightly different sizes—buy for the larger foot. Measure feet at the end of the day when they're slightly swollen for a more accurate fit. Use a Brannock device (the metal measuring tool in shoe stores) for precise length and width measurements, or trace your foot on paper and measure for online purchases.

When shopping online from international retailers, always consult the specific brand's size chart rather than relying on general conversion charts. Read customer reviews mentioning fit—phrases like "runs small," "true to size," or "runs large" provide valuable guidance. Many online shoe retailers now offer virtual try-on features, free shipping, and easy returns, making it less risky to order shoes without trying them on first.

Consider the shoe type when converting sizes. Athletic shoes, dress shoes, boots, sandals, and heels all fit differently even in the same size. Athletic shoes often need more room for foot movement and swelling during exercise. Dress shoes typically fit more snugly. Boots must account for socks thickness and calf width. Heels change weight distribution, sometimes requiring different sizing than flats.

When buying shoes as gifts, include a gift receipt for easy exchanges. If possible, trace the recipient's foot or discreetly check their existing shoes for size information. Be aware that people may wear different sizes in different brands, so knowing someone wears a size 9 Nike doesn't guarantee they wear a size 9 in all brands. Gift cards are often safer than guessing sizes, especially for online purchases from international retailers.

Conclusion

Navigating international shoe sizing requires understanding the different systems used worldwide—US, UK, European, and Asian—and how they relate to each other. While conversion charts provide helpful guidance, remember that actual fit varies by brand, style, and individual foot characteristics. Measuring your feet accurately and consulting brand-specific size guides gives you the best chance of finding well-fitting shoes when shopping internationally.

Whether you're ordering designer heels from Italy, athletic shoes from Japan, or casual footwear from the UK, understanding shoe size conversion empowers you to shop confidently across borders. Use UnitHarbor's conversion tools as a starting point, but always verify with brand-specific charts and customer reviews. Properly fitting shoes aren't just more comfortable—they're essential for foot health and overall well-being.