- Quick Summary: Nike trainers generally fit true to size and offer more width options, while adidas shoes often run slightly shorter and narrower. This guide compares sizing, fit, width, and the best models for different foot shapes.
Buying trainers online is never straightforward. Even if you know your size in one brand, there's no guarantee it'll be the same in another.
Nike and adidas are a good example of this. While both use standard sizing, they don't fit exactly alike. In general, Nike stays true to size, whereas many adidas models fit slightly shorter and can feel a little snug around the forefoot.
Knowing those differences before you buy can save you from ordering multiple sizes or dealing with returns. Here's what you need to know when it comes to Nike vs adidas sizing.
How Should Sneakers Fit?
Before comparing brands, it's worth understanding what a good fit actually feels like.
Much like when comparing ASICS and New Balance trainers, usual principles apply. According to Nike, these are as follows:
Toe Room
Your toes should be able to move naturally without pressing against the front of the shoe. Too little room can lead to discomfort, blisters, and pressure points.
Heel Fit
Your heel should stay firmly in place while walking or running. If it slips excessively, you're much more likely to end up with rubbing or blisters.
Length
Clarks recommends having about a thumb's width between your longest toe and the end of the shoe when standing. This gives your feet enough room to expand during the day without feeling loose.
Flex Point
The shoe should bend where your foot naturally bends — at the ball of your foot rather than through the arch. This is particularly important for running shoes and gym trainers.
These principles apply whether you're buying a performance shoe like the Nike Alphafly 3 or an everyday option such as the adidas Ultraboost.
Nike vs adidas Sizing
Although both brands use standard size charts, the fit isn't identical.
Nike trainers generally fit true to size, so most people can buy their usual size with confidence. adidas, meanwhile, tends to fit a little shorter and slightly narrower, especially in sport-focused models.
If you're between sizes, sizing up by half in adidas is often the safer option.
Quick Comparison
- Nike generally fits true to size.
- adidas often feels slightly shorter.
- adidas can also feel narrower through the forefoot.
- If you're between sizes, consider going up half a size in adidas.
That said, every shoe is different. A Stan Smith won't fit exactly like an Ultraboost, just as an Air Force 1 feels very different from a Vaporfly. Checking reviews for the specific model is always worthwhile.
Nike vs adidas Width
Length is only part of the story. Width can make just as much difference, particularly if you have broad or narrow feet.
Nike Width Options
Nike is one of the better brands for width choices. Many of its running shoes are available in standard, wide and extra-wide versions, making it much easier to find the right fit without changing size.
adidas Width Options
adidas offers wide-fit versions of some shoes, but the information isn't always as clear or consistent. Availability also varies considerably between models, so it's worth checking the product description before ordering.
If you're unsure, customer reviews are often the best indication of whether a particular pair runs narrow or roomy. And because adidas doesn't offer specific width guidance, here are some general pointers on width when it comes to a men's US 8:
- B – Approx. 8.73 cm
- D – Approx. 9.68 cm (standard)
- 2E – Approx. 10.64 cm (wide)
- 4E – Approx. 11.59 cm (extra wide)
Which Nike and adidas Shoes Fit Wide Feet?
If you have wide feet, choosing the right model is often more important than simply sizing up.
Best Nike Shoes for Wide Feet
The Nike Air Force 1 has long been one of Nike's roomiest lifestyle trainers, thanks to its generous toe box and wider overall shape.
For running, the Nike Pegasus 42 is an excellent choice, as it's available in both wide and extra-wide fits without compromising performance.
Best adidas Shoes for Wide Feet
adidas also makes several trainers suitable for wider feet, although they're less common.
Some of the better options can be found in:
Availability depends on the model, so it's always worth checking before buying.
Overall, though, Nike tends to be the better option if you regularly struggle with narrow-fitting shoes.
Which Models Run Narrow?
Some trainers are deliberately designed to fit more closely to improve lockdown and responsiveness.
adidas Shoes That Run Narrow
The aforementioned adidas Ultraboost usually has quite a snug, sock-like fit that hugs the foot, while many Primeknit models wrap tightly around the midfoot for a more secure feel.
If you have wider feet, these may feel restrictive unless you size up.
Nike Shoes That Run Narrow
Nike Flyknit trainers are also known for their close-fitting uppers, with the material stretching around the foot rather than leaving much extra room.
Nike Free series offers a similarly secure fit, using lightweight construction and internal support to keep the foot locked in place.
Final Thoughts
Neither brand is objectively better when it comes to sizing, but there are some consistent patterns.
Nike is generally the safer bet if you want a trainer that fits true to size and offers better width options. adidas shoes often run a little shorter and narrower, so many people find they're more comfortable going up half a size.
In short:
- Nike usually fits true to size.
- adidas often fits slightly small.
- Nike offers more width options across its range.
- Performance-focused models from both brands tend to fit more snugly than lifestyle trainers.
If you can, trying a pair on in-store is still the easiest way to find the right fit. But if you're shopping online, keeping these differences in mind should make choosing the correct size much easier.
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