Shoe Size Conversion Calculator
Free Shoe size conversion tool for clothing & sewing. Enter your details to get instant, tailored results and guidance.
Formula
US Mens = 3 x (foot length in inches) - 22; EU = (cm + 1.5) x 1.5
US sizing is based on the Brannock device formula using foot length in inches. EU uses the Paris Point system where each size = 6.667mm. Japan uses centimeters directly. Conversions approximate due to manufacturer variations.
Worked Examples
Example 1: International Online Shopping
Problem: A man has feet measuring 27 cm. He wants to order shoes from a European retailer and a Japanese retailer. What sizes should he order?
Solution: Foot length: 27 cm = 10.63 inches\nUS Mens = 3 x 10.63 - 22 = 9.89, rounded to 10\nEU Size = (27 + 1.5) x 1.5 = 42.75, rounded to 43\nUK Mens = 10 - 0.5 = 9.5\nJapan = 27 cm\nKorea = 270 mm
Result: US 10 | EU 43 | UK 9.5 | JP 27 | KR 270
Example 2: Converting Womens Sizes Between Systems
Problem: A woman wears US size 8. She wants to know her equivalent sizes for shopping in Europe and the UK. Her foot measures 24.6 cm.
Solution: Foot length: 24.6 cm = 9.69 inches\nUS Womens = 3 x 9.69 - 22 + 1.5 = 8.5 (close to 8)\nEU Size = (24.6 + 1.5) x 1.5 = 39.15, rounded to 39\nUK Womens = 8.5 - 2 = 6.5\nJapan = 24.5 cm\nKorea = 246 mm
Result: US Womens 8 | EU 39 | UK 6.5 | JP 24.5 | KR 246
Frequently Asked Questions
How do shoe sizing systems differ around the world?
Shoe sizing varies dramatically across countries, which is why international conversions are essential. The United States uses the Brannock system, developed in 1927, which measures both foot length and width on a specialized device. Sizes increment in units of one-third of an inch, with separate scales for men, women, and children. The UK system is similar but offset by approximately half a size from US mens. Europe uses the Paris Point system where each size represents 6.667 millimeters (two-thirds of a centimeter), with no distinction between mens and womens sizing for the same foot length. Japan uses the Mondopoint system based directly on foot length in centimeters, which is the most logical and internationally standardized approach. Korea uses millimeters. Understanding these differences prevents costly ordering mistakes when shopping internationally or online from foreign retailers.
Why do shoe sizes vary between brands even in the same country?
Brand-to-brand size variation, known as size inconsistency or vanity sizing, occurs for several reasons. Different manufacturers use different lasts (the three-dimensional forms around which shoes are constructed), and even when targeting the same nominal size, the shape and volume of the last can differ significantly. Some brands size their shoes slightly larger to make customers feel good about fitting into a smaller number, a practice called vanity sizing that originated in clothing. Manufacturing tolerances in mass production mean that even within the same brand, individual pairs can vary by one to two millimeters. Athletic shoe brands tend to run slightly larger than dress shoe brands because they account for thicker athletic socks. European brands converted to US sizing may round differently, creating further discrepancies. The best approach is to know your actual foot length in centimeters and consult each brand specific size chart rather than relying on a universal size number.
What do shoe width letters mean and how are they measured?
Shoe width designations use a letter system that varies by gender and country. In the US system for men, the progression from narrowest to widest is: AAA (extra narrow), AA (narrow), B (narrow-medium), D (standard/medium), E or EE (wide), EEE (extra wide), and EEEE (extra extra wide). For women, the scale shifts: AAA (extra narrow), AA (narrow), B (standard/medium), D (wide), EE (extra wide). Notice that mens standard is D while womens standard is B, reflecting average anatomical differences. Width is measured across the widest part of the ball of the foot. Each width letter represents approximately a quarter inch (6.35 mm) difference in circumference. Many mainstream shoe retailers only stock D width for men and B width for women, but specialty retailers and brands like New Balance offer a full range of widths. People with particularly wide or narrow feet should seek out brands known for offering multiple width options.
How do children shoe sizes work and when should they transition to adult sizes?
Children shoe sizing is divided into several ranges that can be confusing for parents. In the US system, infant sizes run from 0 to 4, toddler sizes from 4 to 7.5, little kid sizes from 8 to 13.5, and big kid sizes from 1 to 7. The numbering resets at size 1 when transitioning from little kid to big kid, which causes frequent confusion. Big kid sizes align with adult sizes in the following way: a big kid size 3.5 roughly equals a womens size 5.5 and a mens size 4. Children typically transition to adult sizing between ages 10 and 14, depending on their growth rate. Children feet grow rapidly, averaging about one full size every three to four months for toddlers, slowing to about one size per year by school age. Always have children feet measured before purchasing, and check fit every two to three months. There should be approximately a thumb width of space between the longest toe and the front of the shoe to accommodate growth.
What are the most common unit conversion mistakes?
Common errors include confusing fluid ounces with weight ounces, mixing up miles and nautical miles, forgetting that UK and US gallons differ (UK is 20% larger), using the wrong temperature formula, and not accounting for the difference between troy and avoirdupois ounces.
How accurate are the results from Shoe Size Conversion Calculator?
All calculations use established mathematical formulas and are performed with high-precision arithmetic. Results are accurate to the precision shown. For critical decisions in finance, medicine, or engineering, always verify results with a qualified professional.