Measurement Standards
Understanding how different regions define shoe and body measurements helps you get reliable conversions. Here we explain the main standards and why centimeters are the most reliable reference.
What Is the Paris Point?
The Paris point is the unit behind European (EU) shoe sizing. One Paris point equals 2/3 of a centimeter (approximately 6.67 mm). EU sizes are built from a baseline (typically a small adult size) and increase by one Paris point per size step.
Because the scale is tied to length in centimeters, EU sizes map more directly to physical foot length than US or UK numeric scales. That’s why many conversion tables use foot length in cm as the bridge between regions.
Why the UK Baseline Differs
UK shoe sizing uses a different baseline and increment than the US and EU systems. Historically, UK sizes started from a different zero point and use a full-size step that doesn’t match US or EU 1:1. As a result, a “UK 8” is not the same length as a “US 8” or “EU 41”—conversion requires a defined offset (e.g. UK men’s often about one size down from US men’s).
UK sizing also traditionally did not use half sizes in the same way as the US, though modern charts often include them. These differences are why we anchor conversions to foot length in centimeters rather than to raw numeric labels.
Why US Widths Exist
In the United States, shoe sizing includes width letters (e.g. N, M, D, EE) in addition to length. This is because US standards (including Brannock-style references) define both length and width. Many other regions don’t use width in the size label—they assume a “standard” width.
When converting from US to EU or UK, we convert length only. If you wear a US wide or narrow width, the same “length” conversion may fit differently in regions that don’t specify width. Our shoe width guide explains how to account for this.
Why CM Is the Most Reliable
Centimeter (CM) measures actual foot or body length. Numeric sizes (US 9, UK 8, EU 42) are regional labels that sit on top of different baselines and increments. Two people with the same foot length in cm might wear different “sizes” in different countries.
Using CM as the reference:
- Removes ambiguity between regional number systems
- Lets you compare your measurement directly to brand size charts
- Makes conversions consistent across our tools
We recommend measuring your foot length in centimeters and then using our shoe size converter or measurement-based guides to get equivalent sizes in US, UK, EU, or other systems.
Sizing Methodology & Data Standards · How to Measure Your Feet in CM
Research: Shoe Size Return Rate Study · Brand Sizing Variation Analysis