Match sizes by foot length (cm), then check model fit — US labels alone can mislead across brands.
Quick answer: Red Wing US 10 ≈ Altra US 10.0 (about 27.3 cm).
Full converter (model + shoes you own) · Reverse: Altra → Red Wing
Static conversion table (crawlable). Interactive tool above uses the same cm matching.
| Red Wing US | cm | Altra US | Altra EU |
|---|---|---|---|
| 6.0 | 23.7 | 6.0 | 38.5 |
| 6.5 | 24.2 | 6.5 | 39.0 |
| 7.0 | 24.7 | 7.0 | 40.0 |
| 7.5 | 25.2 | 7.5 | 40.5 |
| 8.0 | 25.6 | 8.0 | 41.0 |
| 8.5 | 26.1 | 9.0 | 42.5 |
| 9.0 | 26.4 | 9.0 | 42.5 |
| 9.5 | 26.9 | 9.5 | 43.0 |
| 10.0 | 27.3 | 10.0 | 44.0 |
| 10.5 | 27.7 | 10.5 | 44.5 |
| 11.0 | 28.1 | 11.0 | 45.0 |
| 11.5 | 28.6 | 11.5 | 45.5 |
| 12.0 | 29.0 | 12.0 | 46.0 |
| 13.0 | 29.9 | 13.0 | 47.5 |
Even when charts match, lasts differ. Check these guides:
Red Wing: Iron Ranger 8085 · Classic Moc 1907
Altra: Lone Peak 8
Clothes sizing uses a separate compare path.