New Balance vs ASICS Shoe Size — Which Runs Smaller?
New Balance runs about half a US size large compared to ASICS. If you wear New Balance in US 9, start by checking ASICS in US 9.5. Both brands use the same foot-length measurement — the difference is in the last shape, not the conversion formula.
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Switching rule for this pair
At the US 9 anchor, the same 262mm foot maps to ASICS US 9.5. In plain terms: when moving from New Balance to ASICS, go up half a US size.
- New Balance: runs large signal from 50% of buyer-fit data.
- ASICS: true to size signal from 75% of buyer-fit data.
- If you know your foot length in millimetres, use the Size Passport above before trusting a label-to-label switch.
New Balance → ASICS size chart
| US Men (New Balance) | New Balance → ASICS | Foot length |
|---|---|---|
| 7 | 7.5 | 246mm |
| 8 | 8.5 | 254mm |
| 9 | 9.5 | 262mm |
| 10 | 10.5 | 271mm |
| 11 | 11.5 | 279mm |
Fit verdict
- New Balance: Runs large (50% of buyers)
- ASICS: True to size (75% of buyers)
Why the sizes differ
New Balance runs ~0.5 size larger than ASICS.
New Balance foot length is measured in millimetres, then mapped to US size. The ASICS last fits the same foot, but the starting label shifts by about half a US size because of each brand's fit bias — not a different conversion formula.