Shoe Size Conversion - Convert US, EU, UK, CN, JP Sizes

Understanding International Shoe Size Systems

Why Shoe Size Conversion Matters

Shopping for shoes online or from international brands requires understanding different sizing systems. A US size 9 is not the same as EU 9 or UK 9—in fact, they represent vastly different foot lengths. Without proper conversion, you risk ordering shoes that do not fit, leading to returns, frustration, and wasted time.

The global shoe market uses at least 5 major sizing standards: US (United States), EU (European Union), UK (United Kingdom), CN (China), and JP (Japan). Each system evolved independently with different measurement methods and historical origins. Additionally, mens, womens, and kids sizes use different scales even within the same country, further complicating conversions.

Understanding shoe size conversion is essential for: online shopping from international retailers, buying shoes while traveling abroad, purchasing gifts for family and friends, shopping for children whose feet grow rapidly, and comparing prices across different markets. Accurate conversion prevents costly mistakes and ensures comfort.

Major Shoe Sizing Systems Explained

US Sizing (United States)

The US system uses different scales for mens and womens shoes, with womens sizes approximately 1.5 sizes larger than mens for the same foot length. US sizes increment in whole and half sizes (7, 7.5, 8, 8.5, etc.). The system originated from the Brannock Device, invented in 1927, which measures foot length and width. However, manufacturers are not legally required to use standardized sizing, leading to significant variations between brands.

US sizing characteristics: Mens sizes typically range from 6-16, womens from 5-12, and kids from 0-13 (toddler) plus 1-7 (youth). Athletic shoes often run half a size larger than dress shoes. Width options are common but not universal. The system is intuitive for Americans but confusing for international buyers due to the mens/womens split.

EU Sizing (European Union)

EU sizing, also called Continental or French sizing, is based on the Paris Point system. One Paris Point equals ⅔ centimeter (6.67 mm). Sizes increment in whole numbers only (no half sizes), though some brands offer half sizes for certain markets. EU sizes are theoretically unisex—the same foot length uses the same EU size regardless of gender.

EU sizing advantages: Based on actual foot length measurement, providing more objective sizing. No gender distinction simplifies conversion. Widely used across Europe, making it the international standard for many global brands. Common ranges: mens 39-48, womens 35-42, kids 16-39. Each size increment represents approximately 6.67 mm of length difference.

UK Sizing (United Kingdom)

UK sizing is similar to US sizing but typically 1 size smaller for mens shoes and 2 sizes smaller for womens shoes (same foot length). UK sizes use whole and half increments. The system originated from barleycorns—one size equals ⅓ inch or 8.47 mm, originally the length of three barleycorns (historical grain measurement).

UK sizing notes: Used in the UK, Ireland, and some Commonwealth countries. Similar enough to US sizing that approximate conversions work, but precise fit requires exact charts. Some brands show both UK and US sizes on labels. Width fittings are less common than in US shoes. Common ranges: mens 6-12, womens 3-9.

Asian Sizing (China and Japan)

Chinese (CN) sizing: Uses the Mondopoint system based on foot length in centimeters or millimeters. CN 245 means 24.5 cm foot length. Some brands use EU-equivalent numbering (CN 40 = EU 40), while others use actual length. This dual system creates confusion—always verify which CN system a brand uses.

Japanese (JP) sizing: Similar to CN sizing, based on foot length in centimeters. JP 25 means 25 cm foot length. Japanese shoes often run narrower than Western shoes due to average foot shape differences. Many Japanese brands now also provide US/EU size equivalents on labels.

Comprehensive Size Conversion Charts

Mens Shoe Size Conversion

Womens Shoe Size Conversion

How to Measure Your Feet Accurately

Accurate foot measurement is the foundation of finding shoes that fit. Follow these professional measurement techniques used by shoe fitters:

Step-by-Step Measurement Guide

1. Timing matters: Measure feet in the afternoon or evening. Feet swell throughout the day due to activity and gravity, increasing up to 5% in length and volume. Morning measurements may result in shoes that feel tight by day's end.
2. Prepare materials: You need: blank paper (larger than your foot), pencil or pen, ruler or measuring tape (centimeters), and the socks you will wear with the shoes. Standing on carpet compresses padding—use a hard floor.
3. Position correctly: Place paper against a wall. Stand with heel touching the wall, weight distributed evenly on both feet. Standing is critical—feet are longer when bearing weight than when sitting (up to 5 mm difference).
4. Mark the position: Have someone mark the paper at your longest toe (usually big toe, but not always—10% of people have longer second toes). Hold the pencil vertical for accuracy. Mark while standing—do not lift foot then mark.
5. Measure carefully: Measure from the wall edge to the mark in centimeters. Use the inside edge of the mark (closest to heel) for precision. Record measurement to nearest millimeter (e.g., 25.3 cm).
6. Measure both feet: Most people have one foot slightly larger (average difference: 2-5 mm). Always use the measurement from your larger foot when selecting shoe size. About 60% of people have a larger right foot.
7. Add comfort space: Add 0.5-1 cm to your measurement for toe room. Toes should not touch the shoe front when standing. More space needed for running shoes (1-1.5 cm) than dress shoes (0.5 cm).
8. Compare to size charts: Use your measurement in centimeters to find the corresponding size in your preferred system. Our calculator simplifies this—enter your foot length in CM for most accurate conversion.

Understanding Shoe Width Sizing

Length is only half the story—width significantly affects fit and comfort. Width is measured across the widest part of the foot (ball, behind the toes). US sizing has standardized width letters, though not all brands offer width options.

US Width Sizing System

Width fitting signs: Correct width—no pressure on sides of foot, ball area comfortable, no pinching. Too narrow—side bulging over sole, pressure on pinky toe or bunion area, numbness or tingling. Too wide—foot slides side-to-side, heel slips, lack of support at midfoot. Many foot problems (bunions, hammertoes, neuromas) worsen from shoes too narrow.

Brand-Specific Sizing Variations

Despite standard sizing systems, significant variations exist between brands. Understanding brand tendencies helps online shoppers select correct sizes without trying on:

Common Brand Sizing Patterns

• Athletic brands (Nike, Adidas, Puma): Typically run true to size for athletic shoes, though some running models run small (especially Nike womens). Width is usually medium—limited wide options. Performance shoes fit snugger than lifestyle sneakers.
• Dress shoe brands (Clarks, Ecco, Cole Haan): European brands (Ecco, Geox) often run large—size down ½ to 1 size. Traditional dress shoes fit narrower than athletic shoes. Width options more common in quality brands.
• Boot brands (Dr. Martens, Timberland, Red Wing): Dr. Martens run large and wide—size down for most people. Work boots (Timberland, Red Wing) typically true to size but designed for thick socks. Break-in period affects fit—leather stretches ¼-½ size over time.
• Fashion brands (Zara, H&M, ASOS): Fast fashion sizing highly inconsistent—size varies even within same brand. Generally run small, especially Asian fashion brands. Always check customer reviews for fit feedback.
• Luxury brands (Gucci, Prada, Christian Louboutin): Italian luxury brands typically run 1-1.5 sizes small—size up significantly. Narrow last construction (sleek silhouette) means less width than athletic shoes. Expect minimal break-in—luxury shoes should fit immediately.

Kids Shoe Sizing: Special Considerations

Children's feet grow rapidly and unpredictably, requiring frequent size checks. Growth rates vary: infants and toddlers grow approximately 1-1.5 sizes per year, preschoolers (3-5 years) about 1 size per year, school-age children (6-10 years) about ½-1 size per year. Growth spurts cause sudden changes—measure every 2-3 months.

Kids Sizing Categories

• Infant (0-12 months): US sizes 0-4, soft-sole recommended for development. Shoes more for protection than support. Focus on flexibility and room for growth (thumb width space at toe).
• Toddler (1-3 years): US sizes 4-10, learning to walk requires flexible, lightweight shoes. Avoid stiff soles that restrict natural foot motion. Toe room essential as toddlers have not developed toe-off gait pattern.
• Little Kid (4-8 years): US sizes 10.5-3, transitioning to more structured shoes. Still prioritize flexibility and comfort over fashion. Feet growing fastest in this period—check fit frequently.
• Big Kid (8-12 years): US sizes 3.5-7, approaching adult sizing. Can transition to athletic/specific sport shoes. Width becomes more important as arches develop. Pre-teens may enter adult sizing.

Kids fitting guidelines: Check fit every 6-8 weeks during rapid growth phases. Look for thumb width (1-1.5 cm) between longest toe and shoe end. Shoes too small cause ingrown toenails, blisters, and gait problems. Do not buy excessively large shoes "to grow into"—oversized shoes cause tripping and poor support. Replace when less than thumb width remains.

Online Shopping Best Practices

Shopping for shoes online without trying them on requires strategy to minimize returns:

1. Know your foot measurements: Measure both feet in centimeters following our guide. Keep record handy when shopping. Update measurements if weight changes significantly or annually.
2. Check brand-specific charts: Always consult the specific brand's size chart—do not assume standard conversions. Brand charts show how their shoes fit their sizing system.
3. Read customer reviews: Look for comments about sizing—"runs small," "runs large," "true to size," "wide toe box," "narrow heel." Reviews from people with similar foot shapes most helpful.
4. Order multiple sizes if allowed: Many retailers offer free returns. Order your typical size plus ½ size up and down. Try all at home and return what does not fit.
5. Consider shoe type: Athletic shoes generally need more room than dress shoes. Boots need space for thicker socks. High heels fit tighter than flats—often need ½ size larger.
6. Check return policy: Ensure free returns before ordering. Some retailers charge return shipping. Keep all packaging until certain shoes fit. Try indoors only—outdoor wear voids most returns.

When Feet Change: Life Events Affecting Size

Feet are not static—size and shape change throughout life due to various factors:

• Pregnancy: Hormones (relaxin) loosen ligaments, causing arches to flatten. Feet can grow ½-1 full size, often permanently. Swelling adds temporary volume. Measure after pregnancy stabilizes (3-6 months postpartum) before buying new shoes.
• Weight gain/loss: Significant weight changes (±20+ lbs) affect foot volume and arch height. Feet widen with weight gain, may narrow slightly with loss. Changes can be ½ size or more.
• Aging: Foot fat pads thin with age, especially under heel and ball. Arches flatten due to ligament weakening. Feet may lengthen and widen ½-1 size from ages 40-70. Bunions and hammertoes more common, requiring wider toe boxes.
• Medical conditions: Diabetes causes neuropathy and circulation problems—proper fit critical to prevent ulcers. Arthritis changes foot shape. Lymphedema causes swelling requiring larger sizes. Always consult healthcare provider about footwear for medical conditions.
• Athletic training: Long-distance running and high-impact sports can cause temporary foot swelling. Feet may swell up to half size during/after long runs. Many athletes wear ½-1 size larger running shoes than casual shoes.

Additional Resources

For more information on shoe sizing and foot health:

• American Academy of Podiatric Sports Medicine - Professional guidance on athletic footwear and foot health
• American Podiatric Medical Association - Information on proper shoe fit and foot care
• ISO 9407 Shoe Sizing Standard - International shoe size system standards
• American Academy of Pediatrics - Guidelines for children's shoe fit and foot development