ASICS vs Adidas Shoe Size — Which Runs Smaller?
ASICS and Adidas run true to each other — keep your usual size as the starting point when switching. If you wear ASICS in US 9, start by checking Adidas in US 9. Both brands use the same foot-length measurement; the small differences are in last shape, not the conversion formula.
Save this comparison profile
Save your usual ASICS size, then reuse it across brand comparisons without retyping.
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Switching rule for this pair
At the US 9 anchor, the same 262mm foot maps to Adidas US 9. In plain terms: when moving from ASICS to Adidas, keep the same US label.
- ASICS: true to size signal from 75% of buyer-fit data.
- Adidas: true to size signal from 70% of buyer-fit data.
- If you know your foot length in millimetres, use the Size Passport above before trusting a label-to-label switch.
ASICS → Adidas size chart
| US Men (ASICS) | ASICS → Adidas | Foot length |
|---|---|---|
| 7 | 7 | 246mm |
| 8 | 8 | 254mm |
| 9 | 9 | 262mm |
| 10 | 10 | 271mm |
| 11 | 11 | 279mm |
Fit verdict
- ASICS: True to size (75% of buyers)
- Adidas: True to size (70% of buyers)
Why the sizes differ
ASICS and Adidas run about the same size.
ASICS foot length is measured in millimetres, then mapped to US size. The Adidas last fits the same foot, but the starting label stays the same because of each brand's fit bias — not a different conversion formula.