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Adidas Size Guide

Adidas uses standard US/EU/UK sizing. Compare systems in the chart below.

Adidas Sizing: What Makes It Different

Adidas is a German company, and its sizing has European roots even though the brand sells worldwide on the same US/UK/EU three-way scale as everyone else. Unlike Nike, whose numbering is essentially the American standard with international equivalents layered on top, adidas builds its charts around the EU scale first — part of why some models fit slightly differently than a Nike shoe at the “same” listed size.

Boost and Primeknit stretch

Adidas soles and uppers built with Boost foam and Primeknit fabric (Ultraboost, NMD, most current running silhouettes) are noticeably snugger out of the box than a standard mesh sneaker, and they loosen and mould to your foot over the first 10 to 20 wears. That break-in period is exactly why Ultraboost and NMD get flagged as running small — buy true to size and the shoe usually settles into a proper fit within the first couple of weeks.

Originals vs. Performance

Adidas splits its catalogue into two lines that fit differently: Originals (Stan Smith, Gazelle, Samba, Superstar) uses flatter, narrower lasts built for a classic silhouette, while Performance (Ultraboost, running and training shoes) is built with more room through the midfoot for movement. Two adidas shoes in the same size from different lines won't necessarily fit the same.

Adidas kids sizing codes

Adidas kids sizes run as Infant (roughly EU 16–27), then step directly into a junior scale that lines up closely with the adult EU chart, without the separate coded ranges Nike uses. That makes adidas one of the easier brands to size up from a child's last-known measurement.

Buying limited releases

Because adidas runs frequent limited drops, resale and raffle listings sometimes only show one regional size system. If a listing only gives you a UK or EU number, convert it before you buy — a sizing mistake on a limited release is much harder to fix through returns than on a standard retail item.

Sneaker Size Converter

Find your perfect fit across every sizing system, instantly. Convert between US, UK, EU, CM and Korean sizing for men, women and kids — with brand-specific fit guides for Nike, Adidas, Jordan and more.

Men's Sneaker Size Converter

Select your size system, pick your size, and every equivalent appears instantly.

I know my size in
Select your size
US—
UK—
EU—
CM—
Korean—
Enter your foot length above for a size recommendation.

⚠ Sizing varies between brands and styles. These conversions are a guide — always check the brand's own size chart before buying.

Women's Sneaker Size Converter

Select your size system, pick your size, and every equivalent appears instantly.

I know my size in
Select your size
US—
UK—
EU—
CM—
Korean—
Enter your foot length above for a size recommendation.

⚠ Sizing varies between brands and styles. These conversions are a guide — always check the brand's own size chart before buying.

Kids' Shoe Size Converter

Choose an age category, then select your size system for instant conversions across US, UK and EU.

Age category
I know my size in
Select your size
US—
UK—
EU—
CM—
Enter your child's foot length above for a size recommendation.

⚠ Kids' feet grow fast — measure regularly and always allow a little extra room. Check the brand's own chart before buying.

Sneaker Brand Size Guide

Not all sneakers fit the same. Here's how the major brands run relative to your true size — so you know before you buy. We've noted which specific models are affected and how much to adjust.

Brand Fit Adjustment Notes
Nike True to Size None needed Generally TTS across most styles. Air Force 1 fits slightly roomy. React and Pegasus running shoes can run narrow — wide-footer types should consider half a size up.
Adidas Runs Small Go ½ size up Ultraboost and NMD run about half a size small. Stan Smith and Gazelle are TTS but fit narrow — if you have wider feet, go half a size up. Yeezy sizing varies by model.
New Balance True to Size None needed TTS with excellent width options (B through 4E). Known for a comfortable, slightly roomier toe box than Nike. 990, 574 and 550 are all reliably TTS.
Jordan True to Size None needed Most Jordan models are TTS. Air Jordan 1 fits wide and roomy — narrow-foot types can size down half. Jordan 11 runs a touch large; some people prefer half a size down.
Vans Runs Large Go ½ size down Old Skool and Sk8-Hi run slightly long — go half a size down if between sizes. Canvas styles stretch a little with wear. Slip-ons tend to feel roomy, so size down more confidently.
Converse Runs Very Large Go 1–1.5 sizes down Chuck Taylors are famous for running big. Men should go 1 to 1.5 sizes down. Women should go down 2 full sizes (they use unisex sizing). The roomy toe box gets roomier as the canvas breaks in.
Puma True to Size None needed Suede Classic and RS models are reliably TTS. Puma fits slightly narrow across most styles — wider feet may prefer to go half a size up for comfort on longer wear days.
Reebok True to Size None needed Classic Leather and Club C are TTS. Reebok generally fits well across widths. Instapump Fury runs slightly narrow. Classics tend to have a slightly roomier toe box than running styles.

Fit notes reflect general fit across popular models and community feedback. Individual styles may vary. Always check the specific product page for fit recommendations before purchasing.

Sneaker Sizing — Frequently Asked Questions

How do I convert US shoe sizes to EU? +
To convert US men's sizes to EU, add roughly 33 to your US size — so a US 10 is approximately EU 44. For women, add about 31 to your US size, so a US 8 is around EU 38.5. The easiest approach is to use the converter above, which gives you the exact EU equivalent for your size instantly.
What is my shoe size in CM? +
Your shoe size in CM refers to the length of your foot in centimetres. You can measure it by standing on a piece of paper, tracing around your foot and measuring from heel to the tip of your longest toe. A US men's 10 is approximately 28cm, and a US women's 8 is approximately 25cm. Use the foot length helper in the converter above for an instant size recommendation.
Do Nike shoes run true to size? +
Nike shoes generally run true to size, but fit can vary by model. Running shoes like the Pegasus and React Infinity tend to be accurate to your normal size, while lifestyle styles like the Air Force 1 can feel slightly roomy. If you're between sizes in Nike, most people are comfortable going half a size down.
What is the difference between men's and women's shoe sizing? +
Men's and women's shoe sizes use different numbering systems even though they can refer to the same foot lengths. A women's US 8 is roughly equivalent to a men's US 6.5 — women's sizes run about 1.5 sizes larger than men's for the same foot. Women's shoes are also typically made on a narrower last, which matters when buying unisex or crossover styles.
How do I convert kids' shoe sizes to adult sizes? +
Big kids' sizes (Y) run up to a US 7Y, which is close to a US 7 in women's or a US 5.5 in men's. Kids' sizes and adult women's sizes overlap closely — a kids' 5Y is roughly a women's US 6.5. If you have wide feet, adult sizing is usually a better option since it comes in more width choices than kids' shoes.
What shoe size is EU 42 in US? +
EU 42 is a US men's 8.5 or a US women's 11, depending on the gender sizing chart you're using. EU sizes use the same number across men's and women's but the equivalent US size differs between the two. Use the converter above to check both conversions instantly.
Do Converse run big or small? +
Converse sneakers are well known for running big — most people go 1 to 1.5 sizes down from their usual size. The classic Chuck Taylor has a roomy toe box and uses unisex sizing, so women typically need to go down 2 full sizes compared to their normal women's size. If you're a US men's 10 in most brands, start with a Converse 9.

Frequently Asked Questions

Do Adidas shoes run big or small?

Ultraboost and NMD, adidas's Boost-cushioned models, tend to run about half a size small out of the box and loosen up over the first couple of weeks of wear. Originals styles like Stan Smith and Gazelle are closer to true to size but fit narrow, so wider feet may still want to size up.

What is Adidas EU 42 in US?

Adidas EU 42 converts to a US Men's 8.5 or a US Women's 10, depending on which gender chart you're using. Check the specific product listing, since adidas doesn't always default to men's sizing.

Is Adidas sizing the same as Nike?

The size numbers are broadly aligned between the two brands, but adidas's Boost and Primeknit models fit snugger than a comparable Nike shoe until they've broken in. If you wear a consistent size in Nike, it's a reasonable starting point for adidas, but not a guarantee.

What are Adidas kids sizes in EU?

Adidas Infant sizing runs from roughly EU 16 to EU 27, then steps into a junior scale that lines up closely with the adult EU chart from there. That makes it easier to size up a growing child using one continuous EU scale.

Do Adidas Originals and Performance shoes fit the same?

No — Originals (Stan Smith, Samba, Superstar) use a flatter, narrower last built around the classic silhouette, while Performance shoes (Ultraboost and training models) are cut with more room through the midfoot. The same size in each line can feel noticeably different.

How long does it take Adidas Boost shoes to break in?

Most people find Ultraboost and NMD models feel true to size after 10 to 20 wears, as the Primeknit upper stretches to the shape of your foot. If a pair still feels tight after several weeks of regular wear, it's usually a sign to size up rather than wait longer.