Shoe Size Converter

About this calculator

EU 42 is about UK 8.5, EU 43 is UK 9, and EU 44 is UK 10. There is no constant offset to memorise: one EU size (a Paris point) is 6.67 mm of foot length while one UK size (a barleycorn) is 8.47 mm, so the gap between the two numbers widens as sizes rise. This converter translates your shoe size across US (men, women and kids), UK, EU and Japanese (JP/Mondopoint) systems in a single step. Enter your foot length in millimetres, centimetres or inches — or start from a known size in any system — and the calculator shows the equivalent in every other system at once.

How to read your results

Each result row shows the rounded or half-size value standard for that system. The Mondopoint column is the raw foot length in millimetres and serves as the universal anchor. Shoe sizing varies significantly by brand and last; cross-system conversions are approximate — always check the maker's size chart.

How it's calculated

All conversions are routed through foot length in millimetres as a common intermediate. For US men's, the barleycorn formula applies: US men = 3 × (foot mm ÷ 25.4) − 22, where each size increment is one barleycorn (one-third of an inch ≈ 8.47 mm). UK sizes follow the same barleycorn scale but start one size lower: UK = US men − 1. US women's sizes sit 1.5 sizes above US men's for the same foot length: US women = US men + 1.5. US kids' sizes use a separate barleycorn count starting at a different anchor: US kids = 3 × (foot mm ÷ 25.4) − 10. EU sizes are based on the Paris-point system, where one point equals 2/3 cm. The shoe last — not the foot itself — is measured, so a standard 15 mm fit allowance is added before converting: EU = (foot mm + 15) × 3 ÷ 20. Japanese sizing follows the Mondopoint standard: JP = foot mm ÷ 10, expressing the foot length directly in centimetres.

Worked example

Enter a foot length of 270 mm and select Men's. The converter uses the barleycorn-based formula for US and UK, the Paris-point formula for EU, and the direct millimetre-to-centimetre conversion for JP.

US men 9.9 · UK 8.9 · EU 42.8 · JP 27.0 cm · Mondopoint 270 mm. Rounding to half sizes: US men 10, UK 9, EU 43, JP 27.

Frequently asked questions

How do I convert EU shoe sizes to UK sizes?

Convert through foot length rather than by adding a fixed number. EU sizing is the Paris-point system, EU = (foot mm + 15) × 3 ÷ 20, while UK sizing is the barleycorn scale, UK = 3 × (foot mm ÷ 25.4) − 23. Running an EU 42 back through the first formula gives a 265 mm foot, and forward through the second gives UK 8.3, which rounds to a half size of 8.5. EU 43 comes out at UK 9 and EU 44 at UK 10. The gap between the two numbers grows as sizes rise because a Paris point (6.67 mm) is smaller than a barleycorn (8.47 mm), so no single number can be added or subtracted to move between the scales.

Why do US men's and US women's sizes differ for the same foot?

US women's sizes run approximately 1.5 sizes higher than men's for the same foot length. A man with a 270 mm foot wears a US 10 (men's), while a woman with the same foot length wears roughly a US 11.5 (women's). The offset is a historical convention, not a physical difference.

What is a Paris point, and why does EU sizing use it?

A Paris point is 2/3 of a centimetre (approximately 6.67 mm). The EU (or French) system sizes shoes by the length of the shoe last — the foot-shaped mould — rather than the foot itself. The last is typically about 15 mm longer than the foot, so EU sizes run slightly higher than a direct foot-length ratio would suggest.

What is Mondopoint?

Mondopoint (ISO 9407) is an international metric standard that expresses shoe size directly as foot length in millimetres (sometimes also width). Japan's sizing system follows the same principle in centimetres. Because it uses an absolute measurement, Mondopoint removes most of the ambiguity between national systems.

How accurate are the converted sizes?

The formulas follow the barleycorn (US/UK) and Paris-point (EU) models described in ISO 9407 and the Wikipedia "Shoe size" article. They give good approximations, but brands regularly deviate from nominal sizing — a EU 43 from one maker may fit differently from a EU 43 from another. Treat the results as a starting guide and consult the brand's fit chart before purchasing.

Can I convert kids' sizes the same way?

Yes. Select "Kids" and enter the foot length (or a known kids' size). Kids' US sizes use a separate barleycorn scale that starts lower than the adult scale, so the formula is US kids = 3 × (foot in inches) − 10. UK kids' sizes parallel the US kids' scale with a one-size offset, and EU and JP follow the same adult formulas.

Sources

• ISO 9407:2019 — International Organization for Standardization (ISO)
• Shoe size — Wikipedia

Reviewed by the YouCalc Team · Last reviewed June 12, 2026