adidas vs On shoe size
By the length each brand lists, adidas men's US 9 lines up with On US 9. All 15 men's sizes match the same US number.
Men's sizes
15 of 15 matched men's rows are the same US size. The median length difference is 0 mm on the size in cm scale. Every matched row lists the same length, so any difference below is in the size labels.
| adidas US | EU | UK | cm | On US | EU | UK | cm | Diff |
|---|---|---|---|---|---|---|---|---|
| 7 | 40 | 6.5 | 25 | 7 | 40 | 6.5 | 25 | 0 |
| 7.5 | 40 2/3 | 7 | 25.5 | 7.5 | 40.5 | 7 | 25.5 | 0 |
| 8 | 41 1/3 | 7.5 | 26 | 8 | 41 | 7.5 | 26 | 0 |
| 8.5 | 42 | 8 | 26.5 | 8.5 | 42 | 8 | 26.5 | 0 |
| 9 | 42 2/3 | 8.5 | 27 | 9 | 42.5 | 8.5 | 27 | 0 |
| 9.5 | 43 1/3 | 9 | 27.5 | 9.5 | 43 | 9 | 27.5 | 0 |
| 10 | 44 | 9.5 | 28 | 10 | 44 | 9.5 | 28 | 0 |
| 10.5 | 44 2/3 | 10 | 28.5 | 10.5 | 44.5 | 10 | 28.5 | 0 |
| 11 | 45 1/3 | 10.5 | 29 | 11 | 45 | 10.5 | 29 | 0 |
| 11.5 | 46 | 11 | 29.5 | 11.5 | 46 | 11 | 29.5 | 0 |
| 12 | 46 2/3 | 11.5 | 30 | 12 | 47 | 11.5 | 30 | 0 |
| 12.5 | 47 1/3 | 12 | 30.5 | 12.5 | 47.5 | 12 | 30.5 | 0 |
| 13 | 48 | 12.5 | 31 | 13 | 48 | 12.5 | 31 | 0 |
| 13.5 | 48 2/3 | 13 | 31.5 | 13.5 | 48.5 | 13 | 31.5 | 0 |
| 14 | 49 1/3 | 13.5 | 32 | 14 | 49 | 13.5 | 32 | 0 |
Sources: adidas, support.dtb.adidas.com (checked 2026-10-24) · On, www.on.com (checked 2026-10-24)
Women's sizes
14 of 14 matched women's rows are the same US size. The median length difference is 0 mm on the size in cm scale. Every matched row lists the same length, so any difference below is in the size labels.
| adidas US | EU | UK | cm | On US | EU | UK | cm | Diff |
|---|---|---|---|---|---|---|---|---|
| 5 | 36 | 3.5 | 22 | 5 | 36 | 3 | 22 | 0 |
| 5.5 | 36 2/3 | 4 | 22.5 | 5.5 | 36.5 | 3.5 | 22.5 | 0 |
| 6 | 37 1/3 | 4.5 | 23 | 6 | 37 | 4 | 23 | 0 |
| 6.5 | 38 | 5 | 23.5 | 6.5 | 37.5 | 4.5 | 23.5 | 0 |
| 7 | 38 2/3 | 5.5 | 24 | 7 | 38 | 5 | 24 | 0 |
| 7.5 | 39 1/3 | 6 | 24.5 | 7.5 | 38.5 | 5.5 | 24.5 | 0 |
| 8 | 40 | 6.5 | 25 | 8 | 39 | 6 | 25 | 0 |
| 8.5 | 40 2/3 | 7 | 25.5 | 8.5 | 40 | 6.5 | 25.5 | 0 |
| 9 | 41 1/3 | 7.5 | 26 | 9 | 40.5 | 7 | 26 | 0 |
| 9.5 | 42 | 8 | 26.5 | 9.5 | 41 | 7.5 | 26.5 | 0 |
| 10 | 42 2/3 | 8.5 | 27 | 10 | 42 | 8 | 27 | 0 |
| 10.5 | 43 1/3 | 9 | 27.5 | 10.5 | 42.5 | 8.5 | 27.5 | 0 |
| 11 | 44 | 9.5 | 28 | 11 | 43 | 9 | 28 | 0 |
| 12 | 45 1/3 | 10.5 | 29 | 12 | 44 | 10 | 29 | 0 |
Sources: adidas, support.dtb.adidas.com (checked 2026-10-24) · On, www.on.com (checked 2026-10-24)
Convert your exact size
What a chart comparison cannot tell you
Both tables come from brand-wide size charts. They do not capture the shape of a particular model, its width or how it wears. Check the fit notes on the adidas size chart and the On size chart before you buy.