👟 Brand to Brand
Under Armour to On Shoe Size Conversion
Switching from Under Armour to On? Under Armour runs small and On runs true to size, so the size you order changes. Here's the full chart.
A Under Armour 9.5 works out to a On 9 — about half a size down. The chart below has every size.
Under Armour → On: size down half a size
A Under Armour 9.5 is a On 9.
Find your Under Armour size on the left, read across for On:
| Under Armour size | On size | UK | EU | Foot (cm) |
|---|---|---|---|---|
| 7 | 6.5 | 5.5 | 37 | 23.5 |
| 7.5 | 7 | 6 | 38 | 24.3 |
| 8 | 7.5 | 6.5 | 38.5 | 24.7 |
| 8.5 | 8 | 7 | 39.5 | 25.1 |
| 9 | 8.5 | 7.5 | 41 | 25.9 |
| 9.5 | 9 | 8 | 41.5 | 26.3 |
| 10 | 9.5 | 8.5 | 42.5 | 26.7 |
| 10.5 | 10 | 9 | 43 | 27.1 |
| 11 | 10.5 | 9.5 | 43.5 | 27.5 |
| 11.5 | 11 | 10 | 44 | 27.9 |
| 12 | 11.5 | 10.5 | 44.5 | 28.3 |
| 12.5 | 12 | 11 | 45.5 | 28.7 |
| 13 | 12.5 | 11.5 | 46 | 29.1 |
| 13.5 | 13 | 12 | 47 | 29.5 |
| 14 | 13.5 | 12.5 | 47.5 | 29.9 |
| 14.5 | 14 | 13 | 48 | 30.3 |
| 15 | 14.5 | 13.5 | 49 | 31.1 |
| 15.5 | 15 | 14 | 49.5 | 31.5 |
⚠️ Fit varies by model. Under Armour tends to run about half a size small, especially in performance trainers. On (On Running) runs true to size for most, with a snug, performance fit.
On to Under Armour → · Under Armour chart · On chart · Brand finder
What is a Under Armour 9.5 in On?
A Under Armour 9.5 is about a On 9 — they share a foot length of roughly 26.3 cm (UK 8, EU 41.5).
Do Under Armour and On fit the same?
No — Under Armour runs small and On runs true to size, so size down half a size when you switch.
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