ASICS vs New Balance Shoe Size - Which Runs Smaller?

ASICS runs about half a US size small compared to New Balance. If you wear ASICS in US 9, start by checking New Balance in US 8.5. Both brands use the same foot-length measurement; the difference is in the last shape, not the conversion formula.

ASICS to New Balance size chart

Starting New Balance size to check when you wear ASICS in each US men size.
US Men (ASICS) ASICS -> New Balance Foot length
7 6.5 246mm
8 7.5 254mm
9 8.5 262mm
10 9.5 271mm
11 10.5 279mm

Fit verdict

  • ASICS: True to size (75% of buyers)
  • New Balance: Runs large (50% of buyers)

Why the sizes differ

ASICS runs about half a US size small compared to New Balance, with roughly 4mm between the matched fit records.

ASICS foot length is measured in millimetres, then mapped to US size. The New Balance starting size shifts by about half a US size because of each brand fit bias, not a different conversion formula.