Altra to ASICS men's shoe size
The short answer
Altra 4.5 is ASICS 4 or 5 by the two brands' own charts. 1 of 22 Altra sizes land on a different label at ASICS.
At least one of the two brands publishes no foot length, so the rows line up the US size both charts print. Treat it as the label conversion, not a fit.
| Altra | Altra builds it for | ASICS, by chart | Same label | ASICS builds it for | ASICS also prints |
|---|---|---|---|---|---|
| 4 | not published | 4 | not published | not published | US women's 5.5 · UK 3 · EU 36 · CM / JP 22.5 |
| 4.5 | not published | 4 or 5 | not published | not published | US women's 5.5 · UK 3 · EU 36 · CM / JP 22.5 |
| 5 | not published | 5 | not published | not published | US women's 6.5 · UK 4 · EU 37.5 · CM / JP 23.5 |
| 5.5 | not published | 5.5 | not published | not published | US women's 7 · UK 4.5 · EU 38 · CM / JP 24 |
| 6 | not published | 6 | not published | not published | US women's 7.5 · UK 5 · EU 39 · CM / JP 24.5 |
| 6.5 | not published | 6.5 | not published | not published | US women's 8 · UK 5.5 · EU 39.5 · CM / JP 25 |
| 7 | not published | 7 | not published | not published | US women's 8.5 · UK 6 · EU 40 · CM / JP 25.5 |
| 7.5 | not published | 7.5 | not published | not published | US women's 9 · UK 6.5 · EU 40.5 · CM / JP 25.75 |
| 8 | not published | 8 | not published | not published | US women's 9.5 · UK 7 · EU 41.5 · CM / JP 26 |
| 8.5 | not published | 8.5 | not published | not published | US women's 10 · UK 7.5 · EU 42 · CM / JP 26.5 |
| 9 | not published | 9 | not published | not published | US women's 10.5 · UK 8 · EU 42.5 · CM / JP 27 |
| 9.5 | not published | 9.5 | not published | not published | US women's 11 · UK 8.5 · EU 43.5 · CM / JP 27.5 |
| 10 | not published | 10 | not published | not published | US women's 11.5 · UK 9 · EU 44 · CM / JP 28 |
| 10.5 | not published | 10.5 | not published | not published | US women's 12 · UK 9.5 · EU 44.5 · CM / JP 28.25 |
| 11 | not published | 11 | not published | not published | US women's 12.5 · UK 10 · EU 45 · CM / JP 28.5 |
| 11.5 | not published | 11.5 | not published | not published | US women's 13 · UK 10.5 · EU 46 · CM / JP 29 |
| 12 | not published | 12 | not published | not published | US women's 13.5 · UK 11 · EU 46.5 · CM / JP 29.5 |
| 12.5 | not published | 12.5 | not published | not published | US women's 14 · UK 11.5 · EU 47 · CM / JP 30 |
| 13 | not published | 13 | not published | not published | US women's 14.5 · UK 12 · EU 48 · CM / JP 30.5 |
| 14 | not published | 14 | not published | not published | US women's 15.5 · UK 13 · EU 49 · CM / JP 31 |
| 15 | not published | 15 | not published | not published | US women's 16.5 · UK 14 · EU 50.5 · CM / JP 32 |
| 16 | not published | 16 | not published | not published | US women's 17.5 · UK 15 · EU 51.5 · CM / JP 33 |
What wearers say
Charts describe a garment, not a fit. We do not collect fit reports for this category yet, so this table is the two brands' own claims and nothing more.
Sources
- Altra size guide, read on 2026-09-18. Altra on TrueToSize
- ASICS size guide, read on 2026-09-18. ASICS on TrueToSize