Size 39 in US Women’s Shoes: Usually 8.5, Measure First

by YDA UK

Size 39 in US women’s shoes is most commonly 8.5, which corresponds to a foot length of about 25.5 cm (255 mm). Some retailers print a slightly different millimetre figure for the same EU label, so treat the label as a starting point. Measure your foot, then check the brand’s own chart before you buy.

TL;DR:

  • Conversion charts disagree because 255 mm may describe foot length, while a retailer’s 246 mm figure can reflect internal shoe measurement or its sizing convention.
  • Measure both feet against a wall at day’s end, record the longer foot in millimeters, then compare it with the specific brand’s chart.
  • Length does not establish width or fit across styles; check width options, reviews, and toe shape, especially for narrow dress shoes or athletic footwear.
  • For closed shoes, choose the larger size when measurements fall between sizes; for open styles, reviews that report running large may support sizing down.
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Table of Contents

What does EU 39 look like next to US, UK and JP sizes?

Here is a compact reference so you can check labels at a glance. The EU 39 row follows a common industry conversion table, which gives a foot length of approximately 25.5 cm.

Two figures circulate for EU 39. Conversion sites such as MeasKit list 255 mm, while ASOS lists EU 39 as 246 mm in its chart. These are different conventions, not a mistake: one describes foot length, the other often reflects the shoe’s internal measurement or a retailer’s own sizing logic. Consumer charts agree broadly, converting a foot length near 9 7/8 inches to US 8 or 8.5. Use this table as a quick reference, and prefer your measured length wherever you can.

Our own guide to shoe size 39 in UK and US goes further if you also shop in British sizes.

Why do size charts disagree with each other?

The short answer is that shoe sizing systems grew up separately. The European, UK and US systems each started from different units and different traditions, so no single table can translate between them perfectly. ISO 19407:2023, the international standard on converting footwear sizing systems, treats its conversions as guidelines rather than guarantees. It recommends starting from measured foot length, because that is the one number all systems can be compared against.

Brands add another layer. Each one builds shoes on its own last, the foot-shaped mould that defines the interior volume, toe shape and heel fit. Two shoes both labelled EU 39 can have different internal lengths and widths because their lasts differ. Labelling conventions vary too: some brands print EU, US and centimetre figures, and the centimetre figure may describe the foot or the shoe. Nike, for example, warns that printed centimetre or Japanese sizing is not the same as measured foot length.

So the label “39” is not a universal promise of a single US size. It is a good guess that you then confirm. The practical takeaway is simple: measure your foot, convert that measurement using the brand’s own chart, and only then pick a label.

How do you measure your foot to confirm an EU 39?

You need a sheet of paper, a pen, a ruler and a wall. Allow enough time to measure both feet carefully.

  1. Place the paper on a hard floor with one edge against a wall.
  2. Stand on the paper with your heel touching the wall and your weight evenly spread.
  3. Mark the tip of your longest toe with the pen. This is not always the big toe.
  4. Step off and measure from the paper’s edge to your mark in millimetres or centimetres.
  5. Repeat with the other foot and keep the larger measurement.
  6. Compare that figure with the brand’s size chart, not only its EU label.

If your longest foot measures close to 255 mm, EU 39 and US 8.5 are a sensible match on most conversion charts. If it sits nearer 246 mm, a chart like ASOS’s may place you at 39 as well, which shows why the source of the chart matters.

Width matters as much as length. A tape or paper tracing across the widest part of the forefoot tells you whether to look for narrow, standard or wide options. Where a brand lists widths, check them, since length alone does not cover how a shoe feels across the ball of the foot.

Pro Tip: Measure at the end of the day, when your feet are slightly larger, so the shoe is comfortable when it matters most.

For a fuller walkthrough, see our mm-first method for measuring women’s shoe size. Our partner guide on measure-first boot sizing applies the same logic to boots, which is useful if you are shopping for a higher shaft.

What should you check before buying size 39 online?

Online shopping removes the chance to try a shoe on, so you need to replace that with information. A few habits make a large difference.

  • Read the brand’s own size chart on the product page and note the millimetre or centimetre figures, not just the EU label.
  • If a brand lists both EU sizes and centimetres, trust the centimetres for fit.
  • Choose retailers with free or easy returns, and look for a try-at-home window.
  • When you fall between two sizes in closed footwear, favour the larger one, since you can add an insole but you cannot stretch leather indefinitely.
  • Check width options and read customer reviews that mention fit, particularly from people with a similar foot shape.
  • If you are still unsure, contact customer support with your measured length. A direct answer from the brand beats any generic conversion.

Our women’s shoe size chart and fit guide covers extra context on widths and fit notes if you want to cross-check.

How do width sizes relate to EU 39 in US women’s shoes?

EU labels rarely tell you anything about width. A shoe marked 39 usually assumes a standard width, and many European brands do not offer separate width options at all. Some US brands use letter codes for width, but the codes vary. Check the brand’s own width chart. These codes are conventions, and brands apply them differently, so a US 8.5 D from one maker may not feel the same as another’s.

This means there is no clean equivalent of “EU 39 wide”. If you have a broad forefoot, treat 39 as a length figure only. Look for the brand’s width options, and if none exist, check whether the toe box is described as roomy or anatomical. Some people do better with a half size up in a style cut narrow, but this trades length for width, so you risk heel slip and a toe that sits too far forward. Where a shoe is made in one width only, reviews and the brand’s measurements are your best guide.

Measure the widest part of your forefoot as well as the length. Place the tape across the ball of the foot and compare it with any width figures the brand publishes. If there are none, ask support. Matching length first and width second gives you a far better chance of a comfortable fit than relying on the EU 39 label alone.

How do width sizes relate to EU 39 in US women's shoes? — overview diagram

Does size 39 fit the same in sneakers and dress shoes?

Rarely exactly the same. Shoe type changes how a given length feels, so your 39 can shift between categories.

Sneakers and running shoes usually have more padding, a roomier toe box and some give in the upper. Many people find they need a little spare room at the front, about a thumb’s width, because feet swell and slide forward during activity. In athletic styles, some wearers choose a half size above their dress size for this reason.

Dress shoes and heels are tighter and less forgiving. A pointed toe reduces usable length, and a high heel pushes your weight forward onto the toes. A shoe that is fine at flat height can pinch at a heel height, so length and toe shape both matter more here. Leather uppers may soften over time, while synthetic ones usually will not.

Boots add shaft height and often use thicker socks, so a little extra volume can help. Sandals and open styles depend on how the strap sits, and a foot that overhangs the footbed is a sign the size is too small, even if the label says 39.

The lesson is to treat each category on its own terms. Keep your measured length handy and compare it with each brand’s chart for that specific style rather than assuming one size works everywhere.

Fit factors across four shoe categories

When should you size up or down from a standard conversion?

Half sizes exist because feet do not fall neatly into whole steps. In this region of the chart, EU 39 sits at US 8.5, so a half step up or down in US terms is a small change in length. EU sizes typically move in smaller increments than whole US sizes, which is why the two labels never line up perfectly.

Consider going up half a size when a shoe has a pointed or narrow toe, when you plan to wear thick socks or orthotic insoles, when you are between sizes in a closed shoe, or when your measured length sits at the top of the range for 39. Extra length gives toes space and reduces pressure.

Consider going down when a shoe is open at the back, like a mule or sandal, and you measure at the bottom of the range, or when a brand’s reviews consistently say it runs large. A heel that slips in a closed shoe is another sign you may need a smaller size or a snugger fit.

If your two feet differ, fit the larger one and use a heel grip or insole on the smaller. Your measured length and the brand’s chart should outrank any conversion rule, including the one in this article.

Why do we put measurement first?

Fit is the foundation of everything we make. We design high-performance footwear around foot health, and a shoe cannot support your foot properly if it is the wrong length or width. That is why we treat the tape measure as the first tool, not the last, and why we publish measurement guidance rather than expecting you to trust a label.

In our view, the best conversion table is the one you build yourself from your own foot. Labels will keep disagreeing across brands for as long as sizing systems differ, so the dependable approach is to know your own number in millimetres and check it against each chart. Our written guides walk you through exactly that, and our support team can help you interpret your measurements if you are unsure.

— Panagiotis

How can we help you pick the right size?

We offer size charts, a how-to-measure guide and customer support so you can confirm your fit before you order. Everything is meant to be practical and straightforward, with no guesswork about what a label means.

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If you want footwear built around foot health and a measured fit, start with your own numbers and take them to our shop.

FAQ

Is size 39 the same as US 9?

Not usually. Common conversion tables map EU 39 to US 8.5, while US 9 usually corresponds to EU 40. Brands vary, so check the chart for the shoe you are buying.

Is 39 a size 6 or 7 in UK sizing?

EU 39 most often sits at about a UK 6. UK sizing differs by brand, so use your measured foot length and the retailer’s own chart rather than relying on the label alone.

How many centimetres is EU size 39?

Industry conversion tables give approximately 25.5 cm (255 mm) for EU 39. Some retailers list a different figure, so use the brand’s own chart.

Should I size up if I am between sizes?

For closed footwear, favour the larger size, since extra room is easier to manage than a tight fit. For open or slip-on styles, check the brand’s reviews, as some run large and a smaller size may suit you better.

Sources

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