Nike and Adidas are the two biggest sportswear brands, and shoppers often switch between them. Neither brand uses one fixed fit across every product, so the honest answer is: it depends on the line. Here is what to check.
Shoes
Many shoppers find Nike trainers a little narrower through the midfoot and toe box, and some people go up half a size. Adidas lines vary more: running shoes, football boots and lifestyle styles such as the Samba or Gazelle can all feel different. Because experiences vary by model, use your foot length rather than the size on your last pair.
- Measure your foot, as in our guide to measuring your foot for shoe size.
- Compare it with the foot length listed on each brand's own chart.
- If you are between sizes or have wide feet, consider the larger size or a wide fit.
Clothing
Sportswear is often cut to be athletic, so the fit can look closer to the body than a casual brand's. Items marked "slim", "athletic" or "oversized" fit differently from the same size in a standard cut, so read the fit description on each product page.
The practical rule
Do not copy your size between brands. Use your measurements and check each product's size chart. If you are between sizes for clothing, choose the one that matches your preferred fit.
Where to find the details
Our Nike size chart has full measurements for women's, men's and shoe sizes, and our brand size guide uses AI to give a quick view on other brands.
Not sure which size to order?
Ask the AI fit predictor, and choose Nike or Adidas as your brand.
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