Reference & tool
Shoe Size Conversion Chart: EU, US, UK & CM
A quick way to convert between EU, US Men's, US Women's, UK, and CM (foot length) sizing, covering the common adult range from EU 35 to EU 50. Use the calculator for an instant conversion, or scan the full table below.
Sizes are estimates, not guarantees
Every conversion on this page is a general reference, not an official standard. Shoe brands round differently and build on different lasts (molds), so the same labeled size can fit differently between brands, and sometimes between two models from the same brand. Always check the specific manufacturer's own size chart before buying, especially for sizes marked with † below, which commonly vary by half a size or more between brands.
Enter a size and choose which system it's in. We'll estimate the equivalent size in the other four systems by interpolating the reference chart below.
Full conversion chart (EU 35–50)
Rows marked with † are common split points where brands most often disagree by half a size — we've listed a range there instead of a single number.
† = commonly varies by about half a size between brands. US Women's sizing is generally not produced above roughly EU 47 / US Men's 13, so those cells are left blank rather than guessed.
How shoe sizing actually works
Shoe size scales look like simple numbers, but they come from a few genuinely different measurement traditions, which is a big part of why converting between them is never perfectly exact:
- UK sizing is based on units of roughly 1/3 inch (about 8.5mm), historically called "barleycorns," counted from a fixed starting point.
- US sizing uses the same roughly 1/3-inch unit as the UK scale, but starts counting from a different base point, and uses separate men's and women's scales offset by about 1.5 sizes from each other.
- EU sizing (sometimes called "Paris point" sizing) uses a smaller unit, about 2/3 of a centimeter, measured against the internal length of the shoe's last (the foot-shaped mold the shoe is built on). Because this unit is smaller than the US/UK unit, EU sizes climb faster — roughly 1.25-1.3 EU points for every 1 US/UK size.
- CM sizing (also called Mondopoint in its formal ISO version) is simply your foot's length in centimeters. It's the only one of the four that's a direct physical measurement rather than an arbitrary counting scale, which is why it tends to be the most consistent column across brands.
None of these scales account for width or volume — two shoes labeled the same length-based size can still fit very differently around the midfoot and toe box, which matters more the more your foot shape departs from an "average" last.
Why the same size varies between brands
Beyond the different unit systems above, a handful of practical factors explain most of the size differences we run into brand to brand:
- Different lasts. Every brand designs its own last, and most brands use several different lasts across their own lineup — a running shoe and a boot from the same company are rarely built on the same mold, even at the "same" size.
- Rounding at half sizes. Since EU sizes don't map onto US/UK sizes at a clean 1:1 ratio, brands have to round somewhere. Some round EU 45 down to US 11, others round it up to US 11.5 — both are defensible roundings of the same underlying foot length, which is exactly why we show that row as a range.
- Regional target markets. A shoe designed primarily for one region's market sometimes carries sizing conventions from that market even when sold elsewhere.
- Kids'-to-adult transition. Around US Men's 3.5-4, sizing scales reset or overlap with youth sizing, which is a common source of confusion at the small end of the adult range.
None of this means the charts are unreliable — it means they're a starting point. For anything you can't try on in person, check the specific product listing or the brand's own chart before you buy.
A note for flat feet and orthotics
If you're shopping from our best shoes for flat feet guide or one of our category picks — running, walking, work, or gym — a couple of sizing quirks are worth knowing:
- Flat feet often come with a wider forefoot, so a shoe that's technically the "right" length can still feel cramped through the toe box. Where possible, choose a model with a wide-width option rather than just sizing up a full size to compensate.
- If you plan to wear an aftermarket insole or orthotic, it takes up room the shoe's stock insole didn't use. Some people need to size up half a size to fit an orthotic comfortably — but try it before assuming, since not every shoe needs the adjustment.
- Measuring your foot length in CM and checking it against the chart above is a more reliable starting point than assuming your size is identical across every brand you buy.
For more on identifying your arch type before you shop, see our guide on how to tell if you have flat feet.
Frequently asked questions
How do I convert my EU shoe size to US size?
Find your EU size in the chart above and read across to the US Men's or US Women's column. As a rough rule of thumb, US Men's size is roughly EU size minus 33, and US Women's is about 1.5 sizes larger than the equivalent US Men's size. For an exact figure, use the calculator on this page or measure your foot length in centimeters and match it to the CM column, which tends to be the most reliable column across brands.
Are men's and women's shoe sizes actually different, or just relabeled?
For the same labeled length, US Women's sizing is typically the US Men's number plus 1.5 - so a men's size 9 is close to a women's size 10.5 in overall length. But many women's-specific shoes are also built on a narrower last with a lower volume through the heel and midfoot, not just a relabeled men's shoe, so fit can differ beyond the size number alone.
Why does the same size feel different between two shoe brands?
Every brand builds its shoes on its own "last" (the foot-shaped mold used to construct the shoe), and lasts vary in shape, volume, and width even at the same labeled size. A running shoe and a dress shoe from the same brand can also fit differently at the identical size because they're built on different lasts for different purposes.
What's the most accurate way to figure out my true shoe size?
Measure your foot length in centimeters (stand on a piece of paper, mark your heel and longest toe, measure the distance) and compare that to the CM column, since it's a direct physical measurement rather than a brand-specific label. Measure both feet, since they're rarely identical, and size for the larger one.
Should I size up if I have flat feet or wear orthotics?
Not automatically, but it's common. If you add an aftermarket insole or orthotic, it can take up internal volume that the shoe's stock insole didn't use, which sometimes means sizing up half a size for comfortable toe room. Try the shoe with your actual insole before deciding, rather than assuming a half size up is always needed.
What if my converted size falls between two half sizes?
If you're between half sizes, it's generally safer to size up rather than down, especially for shoes you'll wear for standing, walking, or running, since a slightly roomy toe box is more comfortable long-term than a cramped one.
