The Problem Nobody Talks About
Both Nike and Adidas use "EU 42." But they don't mean the same thing.
Nike EU 42.5 = 27.0 cm foot | Adidas EU 42.7 = 27.0 cm foot
Same foot. Different EU numbers. This is why people return shoes.
Men's Size Comparison (Real Manufacturer Data)
| Foot (cm) | Nike US | Nike EU | Adidas US | Adidas EU | Difference |
|---|---|---|---|---|---|
| 25.5 | 7.5 | 40.5 | 7.5 | 40.7 | +0.2 EU |
| 26.0 | 8 | 41 | 8 | 41.3 | +0.3 EU |
| 26.5 | 8.5 | 42 | 8.5 | 42 | Same |
| 27.0 | 9 | 42.5 | 9 | 42.7 | +0.2 EU |
| 27.5 | 9.5 | 43 | 9.5 | 43.3 | +0.3 EU |
| 28.0 | 10 | 44 | 10 | 44 | Same |
Source: Nike.com and Adidas.com official size charts, March 2026.
Key insight: The US sizes are the same (US 9 = US 9), but EU sizes differ. If you buy Adidas EU 42 because you wear Nike EU 42, you might get a shoe that's slightly too tight.
Don't guess — check
Enter your foot length and see your exact size in both Nike and Adidas (plus 50 more brands).
Compare My Sizes →Why the Difference?
- Different "last" shape — Nike tends to be narrower, Adidas slightly wider in the midfoot
- EU sizing is not standardized — there is no international law that says "EU 42 = X mm." Each brand decides.
- Rounding differences — Nike rounds EU to .5 (42, 42.5, 43), Adidas uses .3/.7 (42, 42.7, 43.3)
What About Other Brands?
| Brand | US 9 Means | EU Equivalent | Width Tendency |
|---|---|---|---|
| Nike | 27.0 cm | EU 42.5 | Slightly narrow |
| Adidas | 27.0 cm | EU 42.7 | Standard |
| New Balance | 27.0 cm | EU 42.5 | Standard-wide |
| Hoka | 27.0 cm | EU 42.7 | Standard |
| ASICS | 27.0 cm | EU 42.5 | Slightly narrow |
| Brooks | 27.0 cm | EU 42.5 | Standard |
| Puma | 27.0 cm | EU 42.5 | Standard |
The Real Problem for Online Shoppers
15-40% of shoes bought online are returned because of wrong size. That's not because people are stupid — it's because sizing is inconsistent and confusing.
The solution: measure once, know your size everywhere. FitScan stores your foot measurement and converts it to the correct size for every brand, using real manufacturer data.
Your Size Passport
One measurement. Sizes in 149 brands. Free, instant, no signup required.
Get My Size Passport →FAQ
Q: Is Nike sizing the same as Adidas?
A: US sizes are the same number, but EU sizes differ. For the same 27.0 cm foot: Nike gives EU 42.5, Adidas gives EU 42.7. Width also differs — Nike tends narrower.
Q: Should I size up in Nike?
A: If you have wider feet, yes — Nike runs slightly narrow. If you're between sizes, go up. See full Nike size chart.
Q: I wear Adidas EU 42. What's my Nike size?
A: Adidas EU 42 = 26.5 cm foot. For Nike at 26.5 cm, that's also EU 42 (US 8.5). In this case they happen to match, but at other sizes they diverge. Check your exact conversion.