Shoe Size Converter
There Is No Official Shoe Size Standard
This is the part most conversion charts leave out. US, UK and EU shoe sizes are conventions, not standards. No international body defines them, manufacturers are free to size however they like, and in practice they do.
A US 10 from one brand can fit like a US 9.5 from another. Running shoes tend to run small, dress shoes large, and Italian brands smaller again. That is not a flaw in the chart above, it is the actual state of shoe sizing.
So treat the conversion as a starting point, and lean on the one number that means the same thing everywhere: the length of your foot in centimetres.
How to Measure Your Foot
Two minutes with a piece of paper beats any chart.
- Put a sheet of paper on a hard floor against a wall.
- Stand on it with your heel touching the wall, wearing the socks you would wear with the shoes.
- Mark the paper at the tip of your longest toe. That is not always the big toe.
- Measure from the wall edge of the paper to the mark, in centimetres.
- Do both feet and use the larger measurement.
Measure late in the day. Feet swell over the course of a day by enough to change the size that feels right, which is why shoes tried on in the morning sometimes pinch by evening.
Many brands publish a centimetre or millimetre figure alongside their sizes, often labelled as the last length or foot length. Where they do, match against that number rather than the US or EU one.
Men’s and Women’s Sizes Are Different Scales
In US sizing, a women’s size is roughly 1.5 numbers higher than the men’s size for the same foot length. A women’s 9.5 and a men’s 8 are both around 25.4 cm.
UK sizing works differently again: the men’s and women’s scales are closer, usually about two sizes apart. EU sizing does not formally split by gender at all, which is why a single EU number can appear in both charts.
This matters when buying unisex styles, which most trainers and skate shoes are. They are almost always listed in men’s sizing, so a woman who wears a US 9 is looking for a US 7.5.
Width is the other half of fit and no conversion chart covers it. US brands use letter widths, with D standard for men and B standard for women. If shoes in your size regularly feel tight across the ball of the foot, the problem is width rather than length and going up a size is the wrong fix.
Where EU Sizes Come From
EU sizes use the Paris point, a unit of two thirds of a centimetre, measuring the length of the shoe last rather than your foot. That is why EU sizes climb in steps that do not line up neatly with half sizes in US or UK, and why the conversions above are not a clean formula.
It also explains something people find confusing: EU sizes have no half sizes in the strict sense. A 42.5 is a manufacturer’s addition, not part of the original scale, and not every brand offers them.