Brooks vs ASICS Shoe Size Comparison
ASICS runs about half a US size smaller than Brooks, so you may need to size up. The gap is about 2mm in measured shoe length plus each brand fit bias. Use the table below to convert any Brooks US size to a starting size in ASICS, with UK, EU and CM alongside.
Brooks to ASICS size chart
| Brooks US | ASICS US | ASICS range | ASICS UK | ASICS EU | ASICS CM |
|---|---|---|---|---|---|
| 7 | 7.5 | 6-8.5 | 6.5 | 37 | 25 |
| 8 | 8.5 | 7-9.5 | 7.5 | 38 | 25.5 |
| 9 | 9.5 | 8-10.5 | 8.5 | 40 | 26.5 |
| 10 | 10.5 | 9-11.5 | 9.5 | 41 | 27.5 |
| 11 | 11.5 | 10-12.5 | 10.5 | 42 | 28 |
| 12 | 12.5 | 11-13.5 | 11.5 | 43 | 29 |
| 13 | 13.5 | 12-14.5 | 12.5 | 45 | 30 |
Data confidence
Why Brooks and ASICS differ
That works out to roughly 2mm of real shoe length. We map every size through foot length in millimetres and then re-apply each brand empirical fit offset, so the comparison reflects how the shoes actually fit rather than how they are labelled.
Brand-level estimate: per-model fit can vary by a full size or more within a brand.