Shoe Size Converter

Shoe sizing isn't a single global standard — it's several regional scales (US, UK, EU) laid over the same range of foot lengths, plus Japan's Mondopoint system, which sizes shoes directly by foot length in centimeters (JIS S 5037). Because these scales have different levels of precision, a single EU or UK size can correspond to more than one US half-size — this converter shows the closest match.

Sizing also differs by category: men's, women's, and kids' shoes each use their own scale rather than a shared unisex one, and kids' sizing runs from a "little kid" scale (topping out around 13.5) into a separate "big kid"/youth scale that restarts at 1.

Worked examples:

• Men's US 10 → UK 9, EU 43, JP 27, 27.1 cm foot length
• Men's US 9 → UK 8, EU 41, JP 26, 26.2 cm foot length
• Women's US 8 → UK 6, EU 39, JP 24.5, 24.6 cm foot length
• Kids' US 1 (youth) → UK 13, EU 32, JP 20, 20.1 cm foot length

Only one of these columns is a measurement

The cm column is your actual foot length. Everything else is a convention with history behind it — the US and UK scales descend from the barleycorn, a third of an inch, fixed by English statute in the fourteenth century. Japan's Mondopoint is the odd one out because it is the measurement, rounded to the nearest half centimetre.

So the reliable way to use this converter is to measure your foot once, in centimetres, and treat that number as your size. Everything else becomes a lookup you do per country or per brand, rather than an identity you carry around. If you know only your US size, you are carrying a number that has already been rounded at least once.

How to measure, and why it changes through the day

Stand on a sheet of paper with your heel against a wall, weight on the foot, and mark the end of the longest toe — which is not always the big toe. Measure heel to mark. Do it standing, because a foot under load spreads and lengthens; a seated measurement reads short and is the usual reason a carefully measured shoe still pinches.

Measure both feet and fit the larger one. Most people have a measurable difference between their feet, and the shoe you can't return is the one that fits the smaller. Measure in the evening too: feet swell over a day on them, and they swell more in heat and during exercise. A foot measured first thing in the morning can be several millimetres shorter than the same foot at 6 pm.

That matters more than it sounds, because of how little a size step is worth. Across the men's table, 16 half-size steps span 23.7 cm to 30.5 cm — about 0.43 cm per half size, and 0.42 in the women's table. Roughly four millimetres. A day's swelling is comfortably larger than the gap between two adjacent sizes, which is why time of day changes your answer and why "I'm a 9" is a looser fact than it feels.

The EU scale is coarser, so converting into it loses information

This isn't a rounding quirk, it is structural: EU sizes step in units of ⅔ cm while US sizes step in half-barleycorns, so the scales genuinely don't align. In the men's table here, 6 of the 11 EU values cover two different US sizes each — EU 38 is both US 6 and 6.5, EU 39 is 7 and 7.5, EU 41 is 8.5 and 9, EU 43 is 10 and 10.5, EU 45 is 11.5 and 12, EU 46 is 12.5 and 13. The women's table collides in the same six places.

When you pick an EU size here, the converter returns the smaller of the matching US sizes. That is a defensible choice and not a complete answer: if you know your size in EU terms and are buying US, the true answer is "one of two adjacent half sizes", and the cm column is what breaks the tie. Going the other way — US or UK into EU — is lossless, because you are moving from a finer scale to a coarser one.

Brand variance is bigger than everything above

Here is the part that makes the whole table advisory. A shoe is built on a last — the foot-shaped form the upper is moulded around — and every brand has its own, often several. Two shoes stamped with the same size from different brands can differ by more than the half-size step the table is built on, which means brand-to-brand variation routinely exceeds the precision of the conversion you just did.

It gets worse within a brand: a road running shoe, a trail shoe and a dress shoe from the same maker are built on different lasts for different purposes and will not fit the same. Some ranges are known for running long or short and their buyers simply size around it. Treat this converter as the starting point for finding a brand's own chart, and treat the brand's chart as the starting point for trying the shoe on.

The dimension this table doesn't have

Width. US sizing carries a width letter that most retail listings quietly drop — D is the standard men's width, B the standard women's, with 2E/4E wider and B/A narrower on the men's scale. Most shoes are sold in the standard width only.

A shoe that is the right length and too narrow is the single most common bad fit, and it gets misdiagnosed as being too small — so people size up, which adds length they didn't need without adding much width, and end up with a shoe that slips at the heel and still pinches across the ball of the foot. If that describes every shoe you own, you likely need a wider fitting rather than a longer one.

Fitting rules worth knowing

Leave room at the end — about a centimetre, roughly a thumb's width, between the longest toe and the end of the shoe, measured standing. Your foot slides forward walking downhill and lengthens under load, and a toe meeting the end of a shoe on a descent is how people lose toenails. This is why running shoes usually go up about half a size from your dress size.

Fit the shoe, not the number. Try shoes on at the end of the day, in the socks you'll actually wear, and walk in them. The width should feel supported without pressure at the widest part of the foot, and your heel should not lift. A shoe that needs breaking in to stop hurting is the wrong shoe: leather softens and moulds, but it does not get longer.

To convert between categories, go through the cm column. The three tables here are separate, and switching category clears the selection rather than carrying the number across — a men's 9 and a women's 9 are different physical shoes. Look up your size in the category you know, read the cm figure, and find it in the other table. Published men's-to-women's offsets differ between charts and between brands, so the measurement is the only version of that conversion that survives contact with an actual shoe.