Shoe Size Conversion Explained
Shoe sizes seem like they should be a solved problem — your foot is your foot, regardless of which country you are buying shoes in. In practice the global shoe industry uses several different sizing systems that overlap awkwardly, so a US 10 is a UK 9.5, an EU 44, and roughly 28 centimeters of foot length. This converter handles every common conversion in one place: enter any size in any system and see the equivalents instantly. It works for men, women, and children's shoes, all with system-appropriate scales.
Why So Many Different Systems?
Each major sizing system grew up around a different traditional measurement. The US system uses a scale based on the barleycorn — a third of an inch — with men's sizes starting at 1 (around 8 inches) and going up by a third of an inch per size. The UK system uses the same barleycorn step but starts counting one size lower than the US, which is why a US 10 is a UK 9. The EU system (also called Paris Point) uses two-thirds of a centimeter steps and counts continuously across men's and women's. The Japanese (Mondopoint) system is the most rational — it just lists the actual length of your foot in centimeters or millimeters.
Men's, Women's, and Kids' Scales
The same physical shoe can have multiple "sizes" depending on whether it is sold as men's or women's. In the US system, women's sizes are typically 1.5 sizes higher than men's for the same foot length — so a US men's 8 fits the same foot as a US women's 9.5. The UK system uses the same scale for both men and women. The EU system uses one continuous scale for adults of both genders. Children's sizes restart the count and use much smaller increments because kids' feet grow rapidly. Pick the appropriate tab at the top of the converter to use the right scale.
How to Measure Your Foot Correctly
The most reliable way to find your true shoe size is to measure your foot in centimeters. Stand on a piece of paper with your heel touching a wall, mark the tip of your longest toe, and measure from the wall to the mark. Always do this in the evening when your feet are slightly larger from the day's standing, and always measure both feet and use the larger one. Add about half a centimeter to one centimeter of comfort room — too tight is uncomfortable, too loose causes blisters and reduces support.
Width Matters Too
Length is only half the story. Shoes are also sized by width — typically labeled as Narrow (B for women, B/D for men), Medium (B for women, D for men), Wide (D for women, 2E for men), and Extra Wide (2E for women, 4E for men). This converter focuses on length only because width labeling varies wildly between brands. If your foot feels too tight side-to-side at the right length, try a wider model rather than going up a length size.
Brand Variation
Even within a single sizing system, shoes from different brands fit differently. Nike running shoes are widely considered to run small, requiring a half-size up from your normal size. European brands sometimes run narrow at the heel. Boot makers often run a half-size large to leave room for thick socks. Use the converter to start with the right baseline number, but always check the brand-specific size guide on the seller's site before purchasing.
Frequently Asked Questions
Why is the US women's size higher than men's for the same foot?
Historical convention. Women's shoes were sized starting from a different baseline because they had different lasts (the molds shoes are built around). The convention stuck even after manufacturing standardized.
What is "EUR" or "EU" sizing on Nike or Adidas tags?
That is the European size, the same as what this converter calls EU. It is the most widely-used international standard, especially for athletic shoes.
Are kids' sizes the same scale as adult?
No — kids' US sizes restart at 1 (around the size of a toddler) and go up to 13 before transitioning to adult sizes 1, 2, 3, etc. The kids tab handles this restart automatically.
This shoe size converter is completely free, runs in your browser, and works for any shoe purchase from any country.