Shoe Size Conversion Calculator
Convert a US shoe size to approximate UK, EU, and centimeter foot-length equivalents, for men's or women's sizing.
About these results
CalcSpectrum calculators produce automated estimates using established formulas and the specific values you enter. Because real-world outcomes depend on input accuracy, mathematical assumptions, and rounding conventions, please verify critical figures with an appropriately qualified financial, tax, medical, legal, or other professional, as relevant.
How It's Calculated
Formula
\text{cm} = \text{usSize} + \begin{cases}18 & \text{male}\\16.5 & \text{female}\end{cases} \\ \text{EU} = \lfloor \text{cm} \rfloor + 15There is no single universal shoe sizing standard — sizing varies by manufacturer and even published conversion charts disagree slightly, particularly for women's EU sizes. This calculator uses one specific, documented generic reference chart for men's and women's US-to-UK-to-EU-to-centimeter conversion, cross-checked against multiple independent published charts. Every result here is an approximate reference conversion, not a guaranteed fit for any specific shoe brand — always check a brand's own size chart when possible.
Worked Examples
Men's US 9
- Foot length = 9 + 18 = 27 cm
- UK size = 9 - 0.5 = 8.5
- EU size = floor(27) + 15 = 42
Women's US 8
- Foot length = 8 + 16.5 = 24.5 cm
- UK size = 8 - 2 = 6
- EU size = floor(24.5) + 15 = 39
Frequently Asked Questions
Why does this calculator say the conversions are "approximate"?
Shoe sizing is not standardized across manufacturers — the same US size can fit differently between brands, and published conversion charts commonly disagree by half a size, especially for women's EU sizes. Treat every result here as a reference starting point, not a guaranteed fit.
Why do men's and women's conversions differ for the same US size number?
US men's and women's shoe sizing use different scales for the same foot length — a given foot length corresponds to a different US size number depending on whether it's read off the men's or women's scale, so gender is a required input.
Can I look up a size by foot length instead of my current shoe size?
This version accepts your current US shoe size directly. If you know your foot length instead, find the closest US size whose derived foot length matches, or check the worked examples above for the relationship.