International Shoe Size Guide

7 min read•June 1, 2025•Reviewed: June 1, 2026

✓Reviewed by Apex Conversion Editorial Team · Last reviewed June 1, 2026

Buying shoes internationally — whether online from a foreign retailer or in a store while traveling — requires knowing how size numbering systems differ. A US Men's 10 is not the same as a UK 10 or a European 44, even though all three might fit the same foot. The numbers are on completely different scales.

There are four major shoe sizing systems in common use: US, UK, European (EU), and Japanese (cm-based). Each has separate scales for men and women, and children's sizing adds another dimension. This guide explains how each system works and gives you the conversions you need.

How Shoe Sizing Systems Work

All shoe sizing systems ultimately measure foot length, but they start from different zero points and use different unit increments. The US and UK systems are based on barleycorns — an old English unit equal to 1/3 inch. Sizes increase by one barleycorn (0.333 inch / 8.47 mm) per size. The EU system uses Paris points, where 1 Paris point = 2/3 cm (6.67 mm). Japan simply uses foot length in centimeters.

Because the zero points differ, the numeric values diverge. US men's size 10 corresponds to a foot roughly 27.9 cm long. EU 44 corresponds to approximately the same foot length. UK 9 also fits the same foot. Three different numbers for three different scales — all describing the same foot.

Quick Size Comparison Table

US Men  US Women  EU    UK    cm
──────  ────────  ──    ──    ────
   6      7.5     39    5.5   24.0
   7      8.5     40    6.5   25.0
   8      9.5     41    7.5   26.0
   9     10.5     42    8.5   27.0
  10     11.5     43    9.5   28.0
  11     12.5     44   10.5   29.0
  12     13.5     46   11.5   30.0
  13       —      47   12.5   31.0

The US System

US shoe sizes use separate scales for men and women. Men's sizes typically run 6–16; women's sizes run 4–14. The same numeric size in men's and women's is not the same physical shoe — women's sizes are typically 1.5 sizes smaller than men's for the same foot. A women's size 9 is equivalent to a men's size 7.5.

Half sizes exist in the US system and correspond to a half barleycorn (approximately 4.2 mm). Going up one full size adds about 8.5 mm of foot length.

The EU System

EU sizing does not separate men's and women's on the number — a EU 40 is a EU 40 regardless of gender. In practice, retailers still market separate men's and women's shoes, but the numeric size is unisex. EU sizes run roughly 35–48 for adults.

EU sizes increase in two-thirds centimeter increments. EU 43 corresponds to a foot length of about 27.3 cm; EU 44 to about 28.0 cm. EU sizing is used across most of continental Europe, and the numbers appear on shoes sold in Germany, France, Italy, Spain, and Scandinavia.

The UK System

UK sizing is close to US sizing but consistently offset. UK men's sizes are typically 1 smaller than US men's sizes — a US Men's 10 is a UK 9. UK women's sizes are typically 2 smaller than US women's sizes — a US Women's 8 is a UK 6.

UK sizing is used in the United Kingdom and Ireland, and some British brands (Clarks, Dr. Martens) use UK sizing in their international retail. When buying from a UK retailer, confirm whether sizes are UK or EU.

Quick Tips

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US Men to EU: add 33 to get the approximate EU size. US Men's 10 + 33 = EU 43.
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US Women to EU: add 31. US Women's 9 + 31 = EU 40.
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US Men to UK: subtract 1. US Men's 10 = UK 9.
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When buying shoes online internationally, check the brand's own size guide — many brands run slightly wide or narrow, and a standard conversion may still result in a poor fit.
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Measure your foot length in cm for the most accurate conversions across all systems.

Frequently Asked Questions

Is EU sizing the same as European sizing?

Yes. EU shoe sizes are used across continental Europe and in international retail. They are also sometimes labeled 'EUR' or 'European.' The sizing scale is the same regardless of the label used.

Why do men's and women's shoe sizes differ?

Historically, US and UK shoe sizes were developed with separate scales for men and women to reflect average foot width differences and to standardize lasts (the forms shoes are built on). The numeric offset (women's sizes run about 1.5 higher than men's for the same foot length) has no mathematical basis — it is a convention that stuck.

What is the most accurate way to find my international shoe size?

Measure your foot length in centimeters (stand on paper, trace your foot, measure heel to longest toe). Then use the cm measurement to look up your size in each system. This bypasses conversion uncertainty.