Authentic vs Old Skool
Both are Vans models but they fit differently: Old Skool runs about 0.5 size s larger than Authentic at the same labelled US size.
At US men's 9 on Authentic
If you wear Authentic in US 9, start with Old Skool in US 8.5: go down 0.5 US sizes. The calculation keeps the same foot length anchor, about 258mm, then removes the Authentic fit offset (-0.5) and applies the Old Skool fit offset (+0).
| Model | Recommended US | Foot mm | UK | EU | CM |
|---|---|---|---|---|---|
| Authentic | 9 | 258 | 7.5 | 39 | 26 |
| Old Skool (equivalent) | 8.5 | 258 | 7.5 | 39 | 26 |