How this instrument works
EU shoe sizing technically runs on the Paris point system, where each size step represents 2/3 of a centimeter of internal shoe length — a genuinely different measurement basis from the US scale's third-of-an-inch step. Converted literally, that relationship isn't a flat offset; it drifts slightly as foot length changes. In practice, though, mainstream brand size charts (Nike, Converse, and most general retailers among them) converge on a simpler working rule across the common adult men's range: EU size is US Men's size plus 33.
This calculator uses that constant-offset convention rather than the literal Paris-point formula, because it's what actually shows up on the size charts shoppers compare against. Anchored at the widely published US9=EU42 reference point, adding 33 to any US Men's size in the roughly US6-US12 range reproduces what you'll find on a typical brand's own conversion chart.
Outside that core range, or for women's and children's sizing (which use different scales and different offsets entirely), treat the EU figure as an approximation rather than a guaranteed match — and expect some brand-to-brand variation regardless, since individual shoemakers cut their lasts (the foot-shaped mold a shoe is built on) slightly differently even at a labeled 'same' size.
- Find your US Men's shoe size, from a previous purchase or a US size chart.
- Enter that US Men's size into the calculator.
- Read the equivalent EU size — US Men's size plus 33.
- Use that EU figure when ordering from a European brand's site or checking a European-made shoe's box.
Worked example — ordering from a European shoe brand
An American shopper who normally wears a US Men's 9 wants to order from a German shoemaker's website, which only lists EU sizes. EU size = 9 + 33 = 42 — matching the same US9=EU42 anchor point published across mainstream brand size charts.
The offset holds at other sizes too: a US Men's 10 becomes EU 43, and a US Men's 12 becomes EU 45. Because it's a flat +33 across the core range, there's no need to consult a full conversion table for each size — though for sizes well outside US6-US12, or for a brand known to run its lasts long or short, checking that specific brand's own chart is still worth doing before ordering.
Questions
Why is EU size just US size plus 33, when EU sizing is supposedly based on centimeters?
The literal EU (Paris point) system is centimeter-based and doesn't produce a perfectly flat offset from the US inch-based scale — but across the common adult men's range, roughly US6 to US12, the two systems happen to line up closely enough that a constant +33 reproduces what mainstream brand charts actually publish. It's a practical simplification of a system that's technically metric underneath.
Does the +33 offset hold outside the US6-US12 range?
It gets less reliable outside that core range — the underlying centimeter-based EU system and the inch-based US system don't drift in perfect lockstep at the extremes, so very small or very large sizes may be off by a partial size from a brand's actual chart. For sizes well outside the common adult range, check that specific manufacturer's own size guide.
Why might my EU size not match what's printed inside my actual shoes?
Individual brands run their own lasts, and some cut noticeably long or short relative to the standard anchor points this calculator uses. Athletic shoes, boots, and specialty European brands are common places where actual fit at the labeled EU size deviates from the general conversion. Treat this as a strong starting point for choosing a size to try, not a guaranteed exact match.
Does this work for women's or children's EU sizes?
No — this is scoped to men's sizing. Women's EU-to-US conversion uses a different offset since women's and men's US sizing are themselves numbered differently for the same foot length, and children's sizing is an entirely separate numbering scale that doesn't continue from the adult scale at all.
How is this different from the site's foot-length-based shoe size calculator?
A companion calculator on this site starts from a measured foot length in inches and derives both a US size and this same EU=US+33 figure. This calculator skips the measurement step and starts directly from a US size you already know, which is faster if you don't have a foot measurement handy but do know your usual US size.