Calculator · sample rates, editable · 2026-11-08
Size converter: CN, US, EU, and UK in one place
A listing says 42, your usual shoe is a US 9, and the size chart on the seller page is a blurry image from a different brand. Converting is not a single lookup, because a 42 from one factory is a 42.5 elsewhere and the last (the mould a shoe is built on) changes the fit even when the numbers match. This converter gives you a range across CN, US, EU, and UK for shoes, tops, bottoms, and headwear, and it asks for your foot length in centimetres whenever you have it, because that measurement is the only input the factory actually builds to.
Fill the fields and the result appears here.
How the number is built
No freight rates on this page. The tool holds a sample conversion table, editable, centred on the common footwear ladder: CN 40 about EU 40 about US 7.5 men about UK 6.5. Tops and bottoms use a separate sample ladder keyed by chest and waist in centimetres rather than by a letter, because letter sizes travel badly between regions. Where the table and your foot length disagree, the foot length wins, because it is measured rather than mapped. These tables are our own sample values compiled for planning and they are not an official size chart from any brand or seller.
What each field is asking for
- Category: shoes, tops, bottoms, or headwear. Each carries its own table, and mixing them produces nonsense.
- Source system: CN, US, EU, or UK. This is the label printed on the item you are replacing, not the label on the listing.
- Source size, typed as the exact string on the tag, including half sizes where the system uses them.
- Foot length in centimetres, optional but strongly recommended for shoes. Stand on a sheet of paper with your heel to a wall, mark the longest toe, and measure.
- Gender or last selector for shoes: men, women, or unisex. Unisex shoes typically fit along the men sizing line.
- Brand fit note: pick runs small, true to size, or runs large if you already know the brand. The tool widens the returned range accordingly.
What you get back
A range rather than one number, for example CN 42 maps to roughly EU 42, US 8.5 to 9 men, and UK 7.5 to 8. When a foot length is supplied the tool prefers the length-based row and tells you which one it used. When the brand note is runs small or runs large, the range shifts by half a size and the page says so on the same line, so you know the range is a range and not a precision claim.
The method
Why the arithmetic works this way
If you understand the mechanics you can sanity-check any quote, including ours.
Why a size chart is always a range
Sizing systems were never harmonised. The EU system is based on a Paris point, the UK system grew from barleycorns, and the US system uses inches with different offsets for men and women. On top of that, factories use lasts of different widths and volumes, so a 42 in one model can feel like a 43 in another. Anyone who hands you a single exact number is flattening all of that. This tool returns a range on purpose. If your foot measures 26.5 cm, you will usually be comfortable in the row that brackets that length, and you should prefer the upper end of the range when the shoe is narrow or the brand runs small.
Measure your foot, not your old shoe
People convert from the size printed on their favourite pair, which already carries that brand fit quirks. Measure the foot instead. Put your heel against a wall, stand with weight on the foot, and mark the longest toe, since feet spread under load. Measure both feet and use the larger one; a full size difference between feet is common and harmless. Do it in the evening, because feet swell during the day by a couple of millimetres, which is enough to change the verdict on a tight shoe. Write the centimetre figure down. That number is your anchor across brands, and it is the input this converter trusts most.
What we cannot verify about any listing
We cannot measure the item you are looking at. We cannot check whether a seller size chart has been corrected recently or whether it was copied from another listing, which happens often on aggregator sites. We cannot tell you the width of a last from a product page, only the length. We cannot know whether the pair you receive will match the tag, which is exactly why the quality check step exists elsewhere on this site. And we have no way to know if a listing is a different colourway of the same model with a different factory behind it, though that is a real and common cause of size drift.
Worked example
Numbers you can check against the form
Run one of these rows through the fields above and the output should match.
| System | Label | Chest (cm) | Body length (cm) | US equivalent |
|---|---|---|---|---|
| CN | M | 104 | 68 | S |
| CN | L | 110 | 71 | M |
| CN | XL | 116 | 74 | L |
| EU shoe | 42 | — | insole 27.0 | US 9 |
| EU shoe | 44 | — | insole 28.5 | US 10.5 |
Common questions
Questions about this calculator
My usual size is US 9. What should I order in a CN listing?
Measure your foot first. A 27 cm foot typically lands around CN 44, EU 43, and US 9.5 to 10, which is already above the US 9 many people convert from. If you cannot measure, start from the range this tool returns and pick the upper end when the brand runs small.
Why does the same shoe show different sizes on two sites?
Because the sites are often quoting different sources: the factory label, the seller chart, or a reseller conversion. When they disagree, trust the factory tag on the physical item, which is what the quality check photos should show you.
Do women sizes convert the same way?
No. The US women scale sits roughly one and a half sizes above the men scale in the same physical length, and many unisex shoes are built on a men last. Select men or women in the tool before reading the range, or the result will be off by more than one size.
Should I size up for wide feet?
A larger length does not make a shoe wider in the way people expect, but in practice going up half a size helps when the alternative is a too-narrow fit. If the brand publishes a wide option, that is the better fix. We cannot tell you the width from a listing page.
Related searches
- size converter
- cn size to us size
- eu to us shoe size
- uk size chart
- foot length in cm
- oopbuy shipping calculator
- oopbuy spreadsheet
- oopbuy spreadsheets
Now put a real row through it
The calculator tells you what a parcel costs. The catalogue tells you what goes in it.
- 1,711 rows in the current snapshot
- Both currencies on every row
- Filter by brand or category before you commit
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