Korean shoe size conversion chart: mm to US, UK and EU

Korean shoe sizes look unfamiliar until you realise they are the most logical system in use anywhere. A Korean size is not a code. It is the length of your foot in millimetres.

That makes converting easy in one direction and awkward in the other, because US, UK and EU sizes are not based on foot length in any consistent way. This guide gives you the conversion tables and, more usefully, the method that does not depend on them.

Quick Summary

A Korean shoe size is your foot length in millimetres, rounded to the nearest 5mm. So 265 means a foot 265mm long, and the shoe is built to fit it. Converting to US, UK or EU is approximate in every case, because those three systems were never built around a single measurement, and they disagree with each other by up to a full size depending on the brand.

• Korean sizing is measured, not coded. 250 means 250mm of foot.
• It moves in 5mm steps, which is finer than a US half size at the smaller end of the range.
• Every conversion out of millimetres is approximate. Treat the tables as a starting point.
• Measure once in millimetres and you can shop any system without converting twice.
• Round up, not down, when you fall between two Korean sizes.

Here is the quick version for the most common sizes.

How does Korean shoe sizing work?

Korean sizing follows the Mondopoint principle, which states shoe size as the length of the foot the shoe is designed to fit, in millimetres. A size 265 shoe is made for a 265mm foot. There is no offset, no gendered scale and no historical unit involved.

Sizes are normally offered in 5mm steps, so you will see 230, 235, 240, 245 and so on. Some brands also publish a width figure alongside the length, which is the second half of the Mondopoint system and the part most Western sizing drops entirely.

The practical consequence is that Korean sizing is the same for everyone. There is no separate men's and women's scale, because a 250mm foot is a 250mm foot. When a Korean size chart does show men's and women's columns, it is translating outward into US sizing rather than describing two different Korean systems.

How do you measure your feet in millimetres?

This takes two minutes and makes every conversion in this guide unnecessary.

1. Put a sheet of paper against a wall and stand on it with your heel touching the wall.
2. Stand up, with weight on the foot. Your foot lengthens under load, and a seated measurement reads short.
3. Mark the tip of your longest toe. This is not always the big toe.
4. Measure from the edge of the paper to the mark, in millimetres.
5. Do both feet and use the larger number. Most people have one foot slightly bigger.
6. Measure late in the day, when your feet are at their largest.

That number is your Korean size, rounded up to the nearest 5mm. It is also the single most useful number to know when shopping any other system.

Korean to US, UK and EU: men

Use the millimetre column as the anchor and read across.

A note on the EU column: EU sizing is the least consistent of the three, and two brands can differ by a full size at the same stated EU number. If you only trust one column, trust the millimetres.

Korean to US, UK and EU: women

The women's US scale sits roughly one and a half sizes above the men's for the same foot length, which is why the same millimetre figure appears in both tables against different US numbers. If you are shopping across both ranges, the millimetre column is the only one that stays constant.

What if you fall between two sizes?

Round up rather than down, then deal with the extra room.

The reasoning is asymmetric. A shoe that is slightly too long can be made to work with a thicker sock, a different lacing pattern or an insole. A shoe that is too short cannot be fixed at all, and it will damage your toenails over time.

That said, rounding up is a compromise rather than a solution, and it is why finer sizing increments matter. A range offered in quarter sizes, as Atoms is from US 3.5 to 15, lets you land much closer to your measurement than a system that forces you into 5mm or half size jumps.

If your two feet measure differently by more than about 5mm, fit the larger foot and adjust the smaller one with lacing or an insole rather than splitting the difference. More on what an insole can and cannot fix is in what is the insole of a shoe.

Why is every conversion approximate?

Three reasons, and they compound.

• The systems measure different things. Korean sizing measures the foot. US and UK sizing descend from measurements of the last, which is the mould the shoe is built on, and a last is longer than the foot it fits.
• Brands apply the scales differently. There is no governing body enforcing what a US 9 means, so two brands can differ by half a size while both being correct by their own chart.
• Shoe shape changes the effective size. A pointed toe box needs more length than a rounded one for the same foot, which is why the same person can be two different sizes in two shoes from the same brand.

This is why a conversion chart is a starting point rather than an answer, and why the measurement is worth more than the number on the box.

Why does Korean sizing feel more accurate?

Because it removes a translation step that every other system leaves in.

When you buy a US 9, you are trusting that the brand interpreted a historical scale the same way the last brand did. Nothing guarantees that. When you buy a 270, you are stating a measurement, and the only question left is whether the shoe is built generously or snugly around that measurement. One unknown instead of two.

It also makes a shoe easier to judge from a listing. If a brand publishes both the Korean size and its own internal fit note, you can work out whether to go up or down before the box arrives. Western sizing rarely gives you that, because the number alone carries no information about length.

The limitation is that a length measurement says nothing about volume. Two feet can both measure 270mm and need completely different shoes, because one is high in the instep and the other is flat. Korean sizing is more precise about the one thing it measures, not about everything.

What are the common mistakes?

Four errors account for most of the returns when people buy across systems for the first time.

1. Measuring while seated. Your foot spreads and lengthens when you stand on it. A seated measurement can read five to eight millimetres short, which is a full size of error before you have even started converting.
2. Measuring one foot. Most people have a noticeably larger foot, and buying for the smaller one guarantees that one shoe will be too short.
3. Converting twice. Going from millimetres to EU and then EU to US compounds the error at every step. Convert once, from your measurement straight to the system you are buying in.
4. Trusting a remembered size. Feet change over years, and adult feet commonly lengthen and widen with age. The size you wore at twenty is not evidence about the size you wear now.

A fifth worth adding: do not assume the shape of the shoe is irrelevant. Two shoes built on the same length can fit completely differently if one has a rounded toe box and the other narrows sharply, and no conversion chart captures that.

What should you check before ordering?

Five checks that catch most sizing mistakes when you are buying across systems.

1. Find the brand's own millimetre column. If a brand publishes one, it overrides any general conversion chart including this one.
2. Read the size selector rather than the size guide. The sizes actually offered tell you more than the guide, which often goes stale.
3. Check the increments on offer. Whole sizes, half sizes and quarter sizes are very different propositions when your measurement sits between two numbers.
4. Check the returns terms before you convert anything. Cross system buying has a higher error rate, so an easy return matters more than usual.
5. Note the shape, not just the number. A narrow pointed shoe in your size will not fit like a rounded one in the same size.

If you want the fit checks to run once the shoes arrive, they are in how should sneakers fit. For children, the age based ranges are in the kids shoe size chart by age.

The one habit that removes the problem

Measure both feet in millimetres once, write the larger number down, and keep it in your phone. From then on you are not converting between systems at all. You are matching a measurement against whatever scale a brand happens to use, which is a far more reliable operation than remembering that you are a nine.

It also makes you harder to mislead. When a chart tells you a 270mm foot is a US 9 and the shoe does not fit, you know the chart is the problem rather than your feet, and you can go looking for a brand whose sizing lands closer to your actual measurement.

That is the real argument for finer increments. Quarter sizing is not a luxury feature. It is the difference between a shoe that matches your measurement and one that is merely the closest available compromise.

Frequently asked questions

What does a Korean shoe size mean?

It is the length of your foot in millimetres. A size 265 shoe is built for a 265mm foot, with no offset and no separate scale for men and women.

How do I convert Korean sizes to US?

Measure your foot in millimetres and read across from the millimetre column. As a guide, 250mm is about a US men's 7 or a US women's 8, and 270mm is about a US men's 9 or a US women's 10.

Is Korean sizing the same as Japanese sizing?

Both use foot length in centimetres or millimetres rather than a coded scale, so the numbers line up closely. Always check the brand's own chart, because step sizes and rounding can differ.

Are Korean shoe sizes unisex?

The measurement is. A 250mm foot is 250mm regardless of who it belongs to. Where a Korean chart shows men's and women's columns, it is translating outward into US sizing.

Should I round up or down between Korean sizes?

Round up. A shoe slightly too long can be managed with a thicker sock, different lacing or an insole. A shoe that is too short cannot be fixed and damages toenails over time.

Why do conversion charts disagree with each other?

Because the systems measure different things. Korean sizing measures the foot, while US and UK sizing descend from measurements of the last the shoe is built on, and no body enforces what a US 9 means.

How do I measure my feet in millimetres?

Stand on paper with your heel against a wall, with weight on the foot, mark the tip of your longest toe, and measure from the paper edge to the mark. Do both feet, use the larger figure, and measure late in the day.

Do my feet change size over time?

Yes. Adult feet commonly lengthen and widen over years, so a size you remember from a decade ago is not evidence about today. Re measure every couple of years.