Do Adidas Run Small? A Model-by-Model Size Guide

7 min read · Brand guides

The short answer is: it depends on the model. Adidas makes shoes across wildly different constructions — from knitted Primeknit uppers to leather court shoes to foam-soled running silhouettes — and they don't all fit the same way. "Just size up half in Adidas" is advice that works for some styles and will have you swimming in others.

Here's a model-by-model breakdown of how Adidas footwear actually fits, so you can make an informed call before ordering.

Adidas Ultraboost

Verdict: Size up half a size. The Ultraboost is probably the most common Adidas sizing complaint. The Primeknit upper hugs the foot tightly from the start, and while it does stretch slightly with wear, most people find it fits about half a size small — particularly in the toe box. If you're a US 10, start with a 10.5. People with wide feet should consider going a full size up, as the knit doesn't have much lateral give.

The Ultraboost 23 and later versions have been slightly updated in their upper construction, but the general guidance still holds: half size up is the safe bet.

Adidas Stan Smith

Verdict: True to size, but narrow. The Stan Smith is one of Adidas's most consistent fits. The leather upper doesn't stretch meaningfully, and the shoe is built on a relatively straight last. Most people are fine at their normal size — but the fit is notably narrow. If you have wide feet or a high instep, sizing up half isn't a bad idea, even though the length is accurate. The extra width that comes with the next size up often solves the comfort issue even if the length feels slightly generous.

Adidas Gazelle

Verdict: True to size, slightly narrow. Similar story to the Stan Smith. The Gazelle fits true to size in length for most people, but the suede upper and slim last mean it runs narrow. Wide feet will struggle at their normal size. If you're between sizes in other brands, size up. If your foot is average width, your normal size should work fine.

Adidas NMD

Verdict: Size up half a size. The NMD has a similar Primeknit construction to the Ultraboost and runs small in a similar way. The sock-like upper can feel constricting in your normal size, and the low-profile midsole offers minimal room for foot spread. Half a size up is the consistent recommendation across almost all NMD models. The R1 and R2 behave similarly; the City Sock version (with its taller upper) can be trickier — some people go a full size up there.

Adidas Samba

Verdict: True to size, possibly half up if wide-footed. The Samba has had a major resurgence in recent years, and its sizing gets asked about constantly. The leather upper fits true to size in length, but the classic court-shoe last is narrow. Most people with average to narrow feet are fine at their normal size. If you have wide feet or are between sizes, go half a size up. The Samba does not stretch significantly with wear, so don't count on breaking it in.

Adidas Yeezy (by model)

Yeezy sizing is genuinely model-specific, which makes blanket advice difficult.

Yeezy Boost 350 V2: Size up half. The knit upper is tight and the shoe fits small across the board. This is the most consistent sizing advice across all colourways.
Yeezy Boost 700: True to size. The bulkier construction and wider toe box means the 700 fits more like a standard sneaker. Most people are comfortable at their normal size.
Yeezy Slide: Size up a full size. The slide runs notably small. A US 10 in shoes is typically a Yeezy Slide 11.
Yeezy Foam Runner: Half to full size up. The moulded foam construction has almost no give, and the closed-toe fit runs small. Half a size up is the minimum; people with wide feet should go a full size.

Adidas Forum

Verdict: True to size. The Forum is a retro basketball shoe with a leather upper and a traditional construction. It fits true to size for most people. The silhouette is slightly boxy compared to more modern Adidas styles, which means it's actually one of the more forgiving fits for wider feet within the Adidas range.

Adidas Campus

Verdict: True to size, slightly narrow. Like the Stan Smith and Gazelle, the Campus is a classic suede court shoe that fits true to size in length but can feel narrow. Same advice: if you have wide feet, go half a size up. Otherwise, stay at your normal size.

Once you've figured out which size to order in Adidas, use our Adidas size guide to convert between US, UK, EU and CM — with the full chart for men, women and kids.

View Adidas size guide →

General Adidas Sizing Advice

A few things hold across most Adidas models. First, Adidas shoes with Primeknit uppers (Ultraboost, NMD, most performance running shoes) tend to run small — half a size up is the safe default. Adidas shoes with leather or suede uppers (Stan Smith, Samba, Gazelle, Campus, Forum) tend to run true to size in length but narrow.

Second, Adidas EU sizing is generally reliable for international shoppers. If you know your EU size from other brands, Adidas EU sizes map cleanly to the same foot length. The US conversion is where the small-fitting perception mostly comes from — the same shoe that's marked EU 44 is marked US 10 in the US, and those two things don't quite match the way most people expect.

Third, if you're buying Adidas on resale and you want to be certain, compare foot length in centimetres against the brand's official size chart rather than relying on a number that may have been entered in a different sizing system by the seller.

Disclaimer: Sizing varies between Adidas models and individual production runs. This guide reflects general consensus — always check the specific style's size chart before purchasing.