A shoe size conversion chart is the first thing a buyer looks for before ordering footwear online — and the wrong one quietly ships you a return. Shoes carry the highest return rate in all of fashion e-commerce, around 31% for multi-brand sellers, and sizing is the reason 44% to 70% of those shoes come back. Below is a clean US / UK / EU / CM conversion chart for men and women, plus the part almost every chart leaves out: length is not what fails buyers — width is.
Shoe Size Conversion Chart: Men (US, UK, EU, CM)
These are reference conversions. There is no single global standard, so treat the centimeter column as the anchor and the size numbers as approximate.
| US (M) | UK | EU | Foot length (CM) |
|---|---|---|---|
| 6 | 5.5 | 39 | 24.1 |
| 7 | 6.5 | 40 | 24.8 |
| 8 | 7.5 | 41 | 25.7 |
| 9 | 8.5 | 42–43 | 26.7 |
| 10 | 9.5 | 44 | 27.9 |
| 11 | 10.5 | 45 | 28.6 |
| 12 | 11.5 | 46 | 29.4 |
| 13 | 12.5 | 47–48 | 30.2 |
Shoe Size Conversion Chart: Women (US, UK, EU, CM)
| US (W) | UK | EU | Foot length (CM) |
|---|---|---|---|
| 5 | 3 | 35–36 | 21.6 |
| 6 | 4 | 36–37 | 22.5 |
| 7 | 5 | 37–38 | 23.5 |
| 8 | 6 | 38–39 | 24.1 |
| 9 | 7 | 39–40 | 25.1 |
| 10 | 8 | 40–41 | 25.9 |
| 11 | 9 | 42 | 26.7 |
Quick rules that hold across most of the range: US women's sizes run about 1.5 sizes larger than US men's for the same foot; UK sizes sit roughly 0.5–1 below US men's; EU is unisex and each EU point equals two-thirds of a centimeter. For men, US size + 33 lands close to EU (US 10 ≈ EU 43); for women, US + 31 (US 8 ≈ EU 39).
Why a Length-Only Chart Still Ships Returns
Here is the uncomfortable part. A standard shoe size conversion chart maps one dimension — length — and calls it a day. But a peer-reviewed systematic review found that 58% of wearers are in shoes too narrow, versus 38% too long. Width is the dominant fit failure, and no US/UK/EU number on any chart tells the buyer whether the shoe is a B, D, or EE.
That gap is expensive. The British Footwear Association's member survey puts the median online footwear return rate at 19%, ranging from 2% to 31% depending on assortment. Single-brand direct-to-consumer labels cluster at 12–20%; multi-brand retailers run 25–30%. And 40–60% of online shoe shoppers "bracket" — they order two or three sizes on purpose, planning to send back the ones that miss. Every bracketed pair is a return you pay to process.
So the conversion chart is necessary but not sufficient. It answers "what's my number in your system?" It does not answer the two questions that actually drive fit: how long is my foot in centimeters, and how wide?
The one number that beats every conversion
Foot length in centimeters is the only measurement that survives every sizing system. The Mondopoint system — the sole shoe-size standard with an ISO specification, used by NATO and across ski and athletic footwear — is built entirely on foot length in millimeters. If a buyer measures a 26.7 cm foot, that fact is true whether they shop US, UK, or EU. A size "9" is not.
That is why the highest-converting footwear listings publish the CM measurement for every size, right next to the US/UK/EU numbers, and add a width note. If you sell across borders, this is also where an international size conversion chart earns its keep — the same principle that fixes apparel fit fixes footwear.
What Footwear Sellers Should Publish
If you list shoes online — on your own store or a marketplace — treat the size table as a returns-prevention asset, not a footnote.
- Publish US, UK, and EU columns and a CM foot-length column for every size
- Add a width indicator (narrow / standard / wide, or B/D/2E) — the dominant fit failure
- Give buyers a 20-second "trace your foot on paper, measure heel-to-toe" instruction
- Show the measured insole length of the actual shoe, not just the nominal size
- Flag when a model "runs small" or "runs wide" — brand variation is real; a size 9 differs between makers
- Put the measurement on the product image itself, so it survives being screenshotted or shared
That last point matters more than it looks. A size table lives at the bottom of the page; the image travels everywhere. Putting the exact dimensions and fit note directly on the photo — the same way a clear size chart that reduces returns works for apparel — means the buyer sees the fit fact at the moment of decision, not after they scroll.
The Cost Math Sellers Skip
Documented sizing-technology deployments cut returns 15–30%. To know what that's worth to you, you have to price a single return first — outbound shipping, return shipping, inspection, repackaging, and the units that come back too scuffed to resell. Most sellers wildly underestimate it. Run your real numbers through a return cost calculator before deciding a better size chart "isn't worth the effort" — for footwear, a 5-point drop in return rate usually pays for the work several times over.
FAQ
How do I convert my shoe size from US to EU?
For men, add roughly 33 to your US size (US 10 ≈ EU 43–44). For women, add roughly 31 (US 8 ≈ EU 39). These are approximations — EU sizing is unisex and based on Paris Points of two-thirds of a centimeter each, so confirm against the foot length in centimeters when you can.
What is the most accurate way to find my shoe size?
Measure your foot length in centimeters, heel to longest toe, standing, late in the day. Foot length in CM is the only measurement that maps to every sizing system, which is why the ISO Mondopoint standard uses it directly. Match that number to the brand's CM column rather than trusting a US/UK/EU number.
Why do shoes have such a high return rate?
Shoes are the single most-returned category in online fashion — about 31% for multi-brand sellers — because sizing and fit drive 44–70% of footwear returns, and standard charts only address length while width causes most misfits. Bracketing (ordering multiple sizes to keep one) inflates the number further.
Does a shoe size conversion chart reduce returns on its own?
Partly. A conversion chart removes the US/UK/EU confusion, but it can't fix width or brand-to-brand variation. Pairing the chart with a CM foot-length column, a width note, and the measurement printed on the product image is what measurably lowers size-driven returns.
Is a US women's 8 the same as a US men's 8?
No. US women's sizes run about 1.5 sizes larger than men's for the same foot length, so a women's 8 is close to a men's 6.5. Always check whether a listing's size is stated in men's or women's terms before converting.
Sources & References
- British Footwear Association — Footwear Return Rates Member Survey
- Statista — Most Returned Product Categories Purchased Online
- Shoe size — sizing systems, barleycorn, Paris Point (Wikipedia)
- RunRepeat — Shoe Size Conversion Guide (US, UK, EU, CM, Mondo)
- Mondopoint — the ISO 9407 foot-length sizing system