International Shoe Size Conversion Chart: US, EU, UK and CN

Looking for 39 in US size? Nike lists EU 39 as US Women 8 or US Men 6.5. One European size, two American numbers - and switching brands can change the answer again. This international shoe size conversion chart helps you find the right starting size and shows what to check before ordering.

The letters beside the number matter. EU means European sizing and UK means British sizing, while US women’s and men’s sizes use separate scales, often labelled W and M. To check a particular pair, open Size Guide or Size Chart beside the size options on the brand’s official product page. The Nike screenshot below shows where to find it. Even if you’re buying from GOAT, Macy’s or eBay, use the brand’s official chart to choose your size.

Women’s international shoe size conversion chart

Use this Nike reference to convert US Women 4-13 into EU or UK sizes. The centimeter column is measured Foot Length, not the shoe’s printed CM / JP size. Inch values are calculated from the centimeter measurements and rounded to two decimal places.

Source: Nike women’s footwear guide. Read across one row: US Women 8 corresponds to EU 39 and UK 5.5 in this chart. For a UK to US shoe size lookup, start in the UK column rather than adding a fixed number to every brand’s UK size.

Use the women’s guide linked from a women’s product page, including extended sizes. The presence of a US Men row inside that guide does not make it the men’s product chart. Keep the category of the shoe and the guide together, particularly when comparing foot-length recommendations.

Men’s international shoe size conversion chart

This Nike men’s reference covers US Men 5-15 and includes half sizes. Start with your EU or UK label, or find your measured foot length. Keep the men’s chart separate from the women’s chart even when both display the same EU number.

Source: Nike men’s footwear guide. For US size to EU conversion, start in the first column. Nike’s US Men 9.5, for example, corresponds to EU 43; its printed CM / JP label is a different field from the foot length shown here.

Some UK values repeat in Nike’s published table. Use the row for the shoes you are buying rather than calculating US sizes with a fixed formula.

Common conversions: EU 37-41 and US 9

For EU to US shoe size, use the women’s or men’s column for the pair you are buying. These conversions come from Nike’s adult size charts.

EU 37 in US size: Nike’s adult charts list EU 36.5 and 37.5, but no exact EU 37 entry. Use your measured foot length to choose a row in the relevant Nike chart above.

US 9 shoe size to EU: Nike lists US Women 9 as EU 40.5 and US Men 9 as EU 42.5.

Kids’ shoe size conversion: babies, toddlers and youth

In Nike’s kids’ system, C marks smaller children’s sizes and Y marks youth sizes. After 13.5C, the sequence restarts at 1Y. The following tables keep the brand’s baby/toddler, little-kid and youth references distinct.

Baby and toddler reference

Little-kid reference

Big-kid and youth reference

Source: Nike kids’ footwear guide. The shopping categories overlap; a number such as 10C can appear in more than one guide. Follow the category linked from the actual shoe, and measure the child’s feet instead of choosing from age alone. A new measurement is more useful than the size of a pair the child has nearly outgrown.

Do not carry Nike’s C/Y notation into another brand automatically. In the adidas kids’ chart, the children’s row lists US 2.5 with EU 34 and a 20.8 cm heel-to-toe measurement. Nike’s youth 2.5Y row uses 21.4 cm. This is why a kids’ conversion needs the brand as well as the letters after the number.

Chinese shoe sizes: CN 37, CN 38, CN 39, CN 40 and CN 41

A two-digit CN label has no reliable US equivalent until its scale is identified. A listing might use an EU-style number under a CN heading, while a manufacturer’s label may use millimeters. A converter cannot resolve that ambiguity from “CN” alone.

CN39 and CN40 shoe size in South Africa

The shopper’s location does not establish the system in an overseas listing. For CN39, CN 40 or CN40, ask the seller whether that number represents EU sizing, a millimeter reference or its own size chart. The same question applies to CN 37, CN 38 and CN 41.

If the seller explicitly confirms that its CN 39 option means EU 39, use the EU row for the identified brand and category. If it instead provides a recommended foot length, check that measurement against the official model guide. A reply saying only “US 8” is incomplete without Women, Men or Kids.

For a search such as euro 37 shoe size in South Africa, confirm that the listing actually says EU 37. A local store’s usual numbering does not change the US selector on an American site.

What a CN 275 label tells you

The official Nike China men’s chart pairs China 275 with US Men 9.5 and EU 43. Here, CN 275 and cm 27.5 are printed size references; they are not a measurement taken from the wearer’s foot or the removable insole.

For that US Men 9.5 entry, Nike’s US men’s guide gives Foot Length as 26.7 cm. Do not divide the CN label by ten and use the result as measured foot length. A seller’s recommendation must explain what its centimeter or millimeter column measures.

Why international shoe size conversions differ by brand

One measured foot can lead to different US starting sizes. The comparison below applies the same measurement to Nike women’s footwear guide and the adidas adult chart. For an in-between Nike measurement, the next larger row follows Nike’s own guidance; the adidas entries match its heel-to-toe rows exactly.

At the third measurement the US numbers agree while the EU labels differ. Agreement in one column is not proof that the shoes fit identically. A shoe last is the form used to shape the shoe; it affects the heel, forefoot and toe space. Materials and model construction also affect the available room.

This explains conflicting “39 shoe size in US” answers. For example, Zappos’ general guide lists women’s EU 39 as US 8.5, while Nike lists US Women 8. Use a generic guide to understand the systems, then use the official brand guide to select the pair.

How to measure your feet for a US size chart

Record heel-to-toe length for both feet and use the longer result. Keep that measurement in centimeters: it lets you consult another brand directly instead of converting an already approximate US or EU size again.

1. Wear the socks you intend to use with the shoes. Measure near the end of the day; adidas recommends this timing in its footwear guide.
2. Secure paper on a hard, flat floor. Stand naturally with weight distributed evenly, placing one foot on the paper.
3. Ask someone to mark the back of your heel and the furthest toe with the pencil upright. Measure the straight distance between the marks.
4. Repeat for the other foot. Repeat any uncertain measurement and record the longer reliable result.
5. Use the column named Foot Length or Heel-toe in the official guide. Follow that brand’s instructions when the measurement falls between rows.

Nike’s How To Measure Foot Length section explains the marking method and recommends sizing up between its listed measurements. Do not add an automatic extra centimeter before using a foot-length table; that would change the input the chart expects. Follow any additional room advice given for the exact model.

Half sizes and width: what N, M and W mean

A half size is another length option. A width choice changes the room across the shoe; buying a longer size is not the same adjustment. Check which heading a letter appears under before interpreting it.

Letter codes also depend on category. In the New Balance width guide, standard women’s width is B and wide is D. Standard men’s width is D and wide is 2E, sometimes written EE. Thus D is not “wide” in every shoe, and W beside a paired size number can mean Women rather than Wide.

If length is appropriate but the forefoot needs more room, compare the model’s wide option before moving up in length. The width offered can change with the selected model or color. Recheck Size and Width together after switching variants.

Check the size on two real US product pages

Before adding a pair to your cart, confirm the product category and style code, open its official Size Guide, and check the selector’s units. The Nike example explains paired W/M sizes; the New Balance example shows a separate width choice.

Nike Air Force 1: W 8 and M 6.5 on one button

The Air Force 1 ’07 Suede women’s page uses paired women’s and men’s labels. A button reading W 8 / M 6.5 is one option described on two scales. Someone buying US Women 8 should follow W 8; M 8 would refer to a different option.

The screenshot below highlights W 8 / M 6.5 on an Air Force 1 size selector. The pictured colorway differs from the linked Suede listing; check the guide for the pair you choose.

New Balance 574 Core: Size and Width are separate

The women’s New Balance 574 Core page provides Standard (B) and Wide (D) width choices separately from Size. It also states that this model runs small and suggests considering a size above your usual one. Read that model-specific advice after consulting its women’s chart, rather than transferring the Nike conversion directly.

Fit reviews can help you distinguish comments about short toe room from comments about a tight forefoot. Check that they concern the same model and category. Before payment, also check whether the listing accepts returns, especially for outlet purchases. Sale and final-sale pairs may have different return terms.

UNDbox size checks before international shipping

Use your personal US warehouse address with the UNDbox self-order instructions. When the shoes arrive, you can request a label photo or an insole measurement before packing. The services page lists two product photos for $3 and measurements with photos for $3 per item as separate services.

Please photograph the size label inside both shoes and the size/width label on the box.

Please measure the removable insole from heel to toe and across its widest point, with the tape visible in the photos.

Compare the insole measurements in the warehouse photos with an insole from a comfortable similar shoe. Use your foot measurement for the conversion tables. Review the photos and any return decision while the pair is still at the warehouse. See our US store guide for shopping options and the shipping calculator for delivery estimates.

Frequently asked questions

Does “US shoe size 39” mean an American size?

In the adult ranges covered here, 39 is not a US Women or US Men size. Check whether the seller means EU 39 or CN 39. A missing or incorrect system label should be clarified before selecting an option.

Are US and Canadian shoe sizes the same?

Retailers such as Zappos group US and Canada together in their adult charts. Still check the product category and brand guide: shopping on a Canadian website does not identify the scale of every imported listing.

How do I convert inches to centimeters?

Multiply inches by 2.54. Keep the original measurement when choosing a row; rounded inch values in a comparison table should not introduce an extra sizing step.

Can I use a youth size instead of an adult size?

Only after checking the brand’s stated correspondence and the actual model. Similar length labels do not establish the same width, shape or construction. Use the youth product’s own guide if buying that version.

What if a US store lets me select EU sizes directly?

You can use the EU option if it matches the brand’s guide for that pair. Check the selected system again in the cart; you do not need to replace a clearly identified EU selector with a US number.

Does international forwarding restart the store’s return period?

No. Follow the retailer’s stated start date and deadline. Plan any return while the shoes are at the US warehouse; arrival in your country does not create a new retailer return window.