Sneaker Size Guide: How Nike, Jordan, Adidas & New Balance Fit

Buying the wrong size is the most common and most avoidable sneaker mistake. It's especially painful on the resale market, where returns are often limited or impossible. This sneaker size guide covers how to measure your feet properly, how sizes convert between US, UK, EU, and centimeters, how men's, women's, and kids' sizes relate, and how the most popular models actually fit.

Quick answer: Measure your foot length in centimeters and use the "CM" size on the brand's chart, since it's the most consistent measure across brands. Nike and Jordan men's UK sizes are one size below US, while Adidas and New Balance UK sizes are half a size below US. Women's sizes are usually 1.5 sizes larger than men's for Nike, Jordan, and New Balance, and 1 size larger for Adidas. Some models also run big or small: many people size down half in Air Force 1s and Adidas Sambas and size up half in Yeezy 350s.

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Step 1: Measure Your Feet Properly

Your "usual size" might be off, especially if you've been wearing the same brand for years. Measuring takes two minutes:

1. Measure in the evening. Feet swell slightly during the day.
2. Wear the socks you normally wear with sneakers.
3. Stand on a sheet of paper with your heel against a wall.
4. Mark the tip of your longest toe (not always the big toe).
5. Measure from the wall to the mark in centimeters.
6. Repeat for the other foot and use the larger measurement.

That number is your foot length, and it maps directly to the CM size on most brands' charts. Centimeter sizing (sometimes shown as JP or Mondopoint) is the most consistent way to compare sizes across brands.

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Step 2: Understand Size Conversions

US, UK, and EU sizes don't convert identically across brands. That catches a lot of people out, and it's also a detail counterfeiters sometimes get wrong on size tags.

Nike and Jordan Men's Size Chart

US	UK	EU	CM
7	6	40	25
7.5	6.5	40.5	25.5
8	7	41	26
8.5	7.5	42	26.5
9	8	42.5	27
9.5	8.5	43	27.5
10	9	44	28
10.5	9.5	44.5	28.5
11	10	45	29
11.5	10.5	45.5	29.5
12	11	46	30
13	12	47.5	31

The Same Foot, Three Brands

Here's how a men's US 9 (27 cm) converts across the three biggest sneaker brands:

Brand	US men's	US women's	UK	EU	CM
Nike / Jordan	9	10.5	8	42.5	27
Adidas	9	10	8.5	42⅔	27
New Balance	9	10.5	8.5	42.5	27

Notice the differences: Nike's UK size is a full size below US, while Adidas and New Balance are half a size below. Adidas also uses French EU sizes with fractions (⅓ and ⅔). If you shop by EU or UK size, always check the specific brand's chart.

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Step 3: Men's, Women's, and Kids' Sizes

Men's to Women's

Brand	Women's size =
Nike / Jordan	Men's + 1.5
New Balance	Men's + 1.5
Vans	Men's + 1.5
Adidas	Men's + 1
Converse (Chuck Taylor)	Men's + 2

So a men's 9 in Nike is a women's 10.5, but a men's 9 in Adidas is a women's 10.

Grade School (GS) Sizes

Grade school sizes, marked with a "Y" for youth (for example, 7Y), overlap with smaller adult sizes. In Nike sizing, a 7Y equals a men's 7 and a women's 8.5.

GS pairs often cost less than adult pairs, which makes them a great option for smaller feet. Be aware that GS versions sometimes use different materials, and that some sellers list GS pairs as adult sizes without saying so. Check the size tag. Our guide on how to not get scammed buying sneakers online explains the "GS swap."

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Step 4: Know How Each Model Fits

Even within one brand, models fit differently because they're built on different lasts (the foot-shaped forms shoes are built around). Here's how popular models typically fit, based on common wearer experience. Feet vary, so treat this as a starting point.

Model	Typical fit	Common advice
Nike Air Force 1	Runs about half a size big	Many go half a size down
Air Jordan 1 (High, Mid, Low)	True to size, narrow toe box	Normal size; wide feet may go half up
Air Jordan 4	True to size, snug toe box	Normal size; wide feet often go half up
Nike Dunk Low	True to size, a bit snug	Normal size; wide feet may go half up
Nike Air Max 90	True to size	Normal size
Adidas Samba OG	Runs a little big	Many go half a size down
Adidas Gazelle	True to size to slightly roomy	Normal size or half down
Adidas Campus 00s	Roomy	Many go half a size down
Adidas Yeezy Boost 350 V2	Runs small	Most go half a size up
New Balance 550	True to size, roomy for some	Normal size or half down
New Balance 990, 2002R, 9060	True to size	Normal size; wide widths available on some models
Converse Chuck Taylor / Chuck 70	Runs big	Many go half to a full size down
Vans Old Skool	True to size	Normal size

For a closer look at how the most popular Nike and Jordan lows compare, see our guides to the Jordan 1 High vs. Mid vs. Low and the Nike Dunk Low vs. Jordan 1 Low.

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Step 5: Don't Forget Width

Length is only half of fit. If sneakers always feel tight across the sides of your foot, width is probably the problem, not length.

• Standard widths: D for men, B for women
• Wide: 2E for men (D for women)
• Extra wide: 4E for men

New Balance is known for offering wide widths on many models, including the 990 series and many running shoes. Most lifestyle sneakers from other brands come only in standard width, so wide-footed buyers often go up half a size instead.

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How to Try On Sneakers (and Get It Right)

• Try them on late in the day with the socks you'll wear.
• Check toe room: you want roughly a thumb's width (about 1 cm) between your longest toe and the front of the shoe.
• Check the heel: your heel shouldn't lift noticeably when you walk.
• Check the width: the widest part of your foot should sit comfortably at the widest part of the shoe, with no pinching.
• Walk around. Don't judge fit sitting down.
• Don't count on stretching. Leather may give slightly in width with wear, but sneakers don't stretch in length, and synthetic materials barely stretch at all.

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Buying Sneakers Online Without Sizing Regrets

1. Know your CM size for each brand you buy.
2. Check the model's fit notes (see the table above) and read recent reviews.
3. Buy from retailers with free returns when you're unsure, then buy resale once you know your size.
4. Keep tags and boxes intact until you're sure the fit is right.
5. Double-check the size tag when a secondhand pair arrives. The size conversions on the tag should follow the brand's chart. Our guide to the Nike shoe tag explains what to look for.

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Frequently Asked Questions About Sneaker Sizes

Are Nike and Adidas sizes the same?

The US sizes are nominally the same, but the UK and EU conversions differ, and individual models fit differently. A US 9 in both brands is about 27 cm, but Adidas labels it UK 8.5 and EU 42⅔, while Nike labels it UK 8 and EU 42.5.

How do I convert women's sneaker sizes to men's?

For Nike, Jordan, New Balance, and Vans, subtract 1.5 from the women's size (women's 10.5 = men's 9). For Adidas, subtract 1. For Converse Chuck Taylors, subtract 2.

Should I size up or down in sneakers?

It depends on the model. Many people size down half in Air Force 1s, Adidas Sambas, and Converse, and size up half in Yeezy 350s. Jordan 1s, Dunks, and most New Balance models fit true to size for most people.

Do Jordans run small?

Most Jordans fit true to size. Some models, like the Jordan 4, have a snug toe box, so wide-footed wearers often go up half a size.

What size is 27 cm in sneakers?

27 cm corresponds to a men's US 9 in Nike, Jordan, Adidas, and New Balance sizing. That's a Nike women's 10.5 and an Adidas women's 10.

What does GS mean in sneaker sizes?

GS stands for grade school, sizes for older kids marked with a "Y" (such as 7Y). In Nike sizing, a 7Y equals a men's 7 and a women's 8.5.

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The right size starts with a two-minute measurement and ends with knowing how each model fits. Shop by centimeters, learn your brand conversions, and check model-specific fit before you buy. Your feet (and your resale returns) will thank you.