Three numbers for one shoe
The warehouse says EU 42, because that is what the carton and the packing list carry. The storefront says US men's 8.5-9, because that is the scale the customer shops in. The spec sheet says 26.5-27 cm, because that is the foot length the size was graded to. None of these contradict each other - they are three layers of the same fact. A buyer who publishes only one layer spends the season answering the other two by email, one ticket at a time, and every one of those tickets is a return that has not happened yet.
The desk keeps the three layers together in every sizing conversation. Stock cartons are marked in EU sizes: most models run 36-45, and some women's and kids' runs sit at 36-41. Retail customers in the United States ask in US scales, and US scales come in more than one flavor - men's, women's and youth are separate ladders that do not share steps. The centimeter column is the anchor that never moves, because a foot measured heel to longest toe, standing, is the same measurement in every country and every scale.
When a layer goes missing, the questions do not disappear - they migrate to support. A storefront that shows only US sizes hears "what is this in EU" from wholesale contacts and "what is this in centimeters" from customers who measured their feet. A chart with only letter sizes hears nothing and simply ships more exchanges. Publishing the three layers together is not thoroughness for its own sake; it is the difference between a page that answers and an inbox that does.
The conversion table, with its limits
This is the mapping the desk works from. It is approximate on purpose: footwear brands grade differently, and two styles from the same line can sit half a step apart on the foot. Final size grading is confirmed on the spec sheet for each program - the table is for planning ranges and answering customer questions, not for replacing the program documents.
| EU | US men | US women | Foot length (cm, approx) |
|---|---|---|---|
| 36 | 4 | 5.5-6 | 22.5-23 |
| 37 | 4.5-5 | 6-6.5 | 23-23.5 |
| 38 | 5.5-6 | 7-7.5 | 24-24.5 |
| 39 | 6.5-7 | 8-8.5 | 24.5-25 |
| 40 | 7-7.5 | 8.5-9 | 25-25.5 |
| 41 | 8-8.5 | 9.5-10 | 26-26.5 |
| 42 | 8.5-9 | 10-10.5 | 26.5-27 |
| 43 | 9.5-10 | 11 | 27.5-28 |
| 44 | 10-10.5 | 11.5-12 | 28-28.5 |
| 45 | 11-11.5 | 12.5-13 | 29-29.5 |
Two features of this table matter more than any single number. First, the foot-length bands overlap: 23 cm appears at the top of EU 36 and the bottom of EU 37, which is why some customers sit on a boundary and can honestly wear either size. Second, the US columns carry half sizes while the EU column moves in whole steps - so a customer between US halves maps to the EU step whose band holds their measurement, and the other US figures in that row are the honest range to quote.
Reading the chart the way a buyer reads it
When the desk checks a size run against a market, the centimeter column does the work. A foot measured standing, heel to longest toe, drops into one band or straddles two - and the straddlers are where size questions come from. For a range plan, the bands also show which EU steps carry the demand: a market that measures mostly 25-27 cm is shopping the EU 40-42 rows, so what matters is that those steps are inside the runs you order. How the steps are distributed inside a carton is fixed - the run steps 1-2-3-3-2-1 across the six size steps - and that distribution is part of the program sheet, not a guess.
One more ladder belongs in the conversation even though it is not in the table: the youth scales. US kid and youth sizes are separate ladders from the men's and women's columns, and they are the ones parents actually shop. The desk's answer is the same as for the adult scales - anchor on the centimeter band, print the EU step, and confirm whatever scale a kids' program needs printed on the spec sheet. The kids' side gets a full treatment in the note on kids shoe sizing.
The table also settles the men's-versus-women's question at a glance, which is worth its own note elsewhere. And it explains why the desk never answers "what US size is EU 41" with a single figure: the honest answer is a row, not a cell. For the measuring side - how a customer produces a foot length worth trusting - see the companion note on how to measure foot size, because the chart is only as good as the number fed into it.
For sellers: one chart, published properly
A size chart earns its place on a product page when it settles questions without a support ticket. The pattern that works is simple. One chart for the whole site, not a different one per product. Both US scales shown, clearly labeled. The centimeter column beside them, because it is the column that survives brand differences. A short note that the mapping is approximate and brands vary. And a link to a measuring guide, so the centimeters your customers send you were taken the same way every time.
Placement matters as much as content: put the chart next to the size selector, where the question actually happens, and repeat it on a hub page it can be linked to from anywhere - the desk keeps one on the shoe size chart page for exactly this purpose. For a sourcing conversation the chart has one more job: it becomes the language you and the factory share. When a program is discussed in EU steps and centimeter bands at the same time, the spec sheet that comes back can be checked line by line, and that check is what keeps a whole season's size runs honest. If you are planning a range and want your size runs mapped to your market, send the brief through the request form and the desk will confirm the grading in writing. The bulk-buying side of the same table is covered in EU to US conversion for bulk buyers, and the women's-scale half of it in men's to women's conversion.