Shoe Size Conversion Guide for Online Shopping
How to use size charts without pretending they are perfect.
Shoe size conversion looks easy until you actually buy shoes from another region. One chart says EU 42 is UK 8 and US men 9. Another says something slightly different. Then the shoe arrives and still feels off.
The first thing to accept is that no simple chart can solve brand differences completely. The shape of the last, the width of the shoe, the style of the footwear and the manufacturer's own sizing habits all affect the final fit. Still, a sensible size converter can cut through the chaos and give visitors a starting point that is far better than guessing.
The right design is practical. Keep the comparison tool near the top. Under that, tell the truth: use the chart as a range, then compare brand notes and return policy.
Why shoe size charts disagree
There are four sizing systems in common use, and they were never designed to line up neatly. EU sizes use the Paris point, where each full size is two thirds of a centimetre (about 6.67 mm). UK and US sizes use the barleycorn, where each size is one third of an inch (about 8.47 mm), and they start counting from different zero points. US women's sizes are usually the US men's number plus 1.5. Centimetre sizing (sometimes labelled Mondopoint) simply states the foot length directly.
On top of those system differences, every brand cuts its shoes around a different last (the foot-shaped mould). Two shoes both marked EU 42 can fit a full size apart if one brand runs narrow and the other runs wide. That is why a conversion chart is a starting point, not a guarantee.
Measure your foot first: centimetres are the honest anchor
The most reliable number is your own foot length in millimetres, because it removes the guesswork between systems. Measure it once and you can shop in any region.
- Stand on a sheet of paper with your heel against a wall, in the evening when feet are largest.
- Mark the tip of your longest toe and measure heel to mark in millimetres.
- Measure both feet and use the larger one.
- Add 5 to 10 mm of toe room for walking shoes, slightly more for running shoes.
Approximate size cross-reference (men's)
Use this as a range, then confirm against the brand's own chart. The foot-length column is the value to trust when sizes conflict.
| Foot length | EU | UK | US men |
|---|---|---|---|
| 24.5 cm | 39 | 6 | 6.5 |
| 25.0 cm | 40 | 6.5 | 7.5 |
| 25.7 cm | 41 | 7.5 | 8 |
| 26.3 cm | 42 | 8 | 8.5 |
| 27.0 cm | 43 | 9 | 9.5 |
| 27.6 cm | 44 | 9.5 | 10.5 |
| 28.3 cm | 45 | 10.5 | 11 |
| 29.0 cm | 46 | 11 | 12 |
For US women's sizes, add roughly 1.5 to the US men's number (US men 8.5 is about US women 10). For children's sizes the systems diverge even more, so always measure foot length and check the brand chart.
Convert between EU, UK and US step by step
Say a German store lists a shoe as EU 43 and you normally buy US. From the table, EU 43 is about US men 9.5 and UK 9, which matches a foot length near 27 cm. Enter the size in the converter to see all systems at once, then check the brand's notes before ordering.
How to buy online without getting burned
- Anchor on foot length in cm, not on the size number you usually wear.
- Read the brand's size notes and search reviews for "runs small" or "runs large".
- For wide feet, size up by a half rather than squeezing into the nominal size.
- Check the return policy before buying, especially across borders where returns cost more.