Brand guide
On Running size chart & fit
On runs true to size with a low-volume, narrow last. Wide-footed runners typically size up 0.5.
Sizing philosophy
Swiss engineering — CloudTec pods and Speedboard. Lasts are narrow and low-volume, built for efficient forefoot runners.
How On Running shoes fit
Cloudmonster, Cloudsurfer, Cloudrunner: true to size but narrow. Cloud 5, Cloud X: 0.5 small — most people size up. Cloudultra: true to size with more toe box room.
Width & last
Narrow standard; no Wide option. Not recommended for very wide feet without sizing up.
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Men's shoe sizing
| US | UK | EU | CM |
|---|---|---|---|
| 6 | 5.5 | 39 | 24.0 |
| 6.5 | 6 | 39.5 | 24.5 |
| 7 | 6.5 | 40 | 25.0 |
| 7.5 | 7 | 40.5 | 25.4 |
| 8 | 7.5 | 41 | 26.0 |
| 8.5 | 8 | 42 | 26.5 |
| 9 | 8.5 | 42.5 | 27.0 |
| 9.5 | 9 | 43 | 27.5 |
| 10 | 9.5 | 44 | 28.0 |
| 10.5 | 10 | 44.5 | 28.5 |
| 11 | 10.5 | 45 | 29.0 |
| 11.5 | 11 | 45.5 | 29.5 |
| 12 | 11.5 | 46 | 30.0 |
| 13 | 12.5 | 47.5 | 31.0 |
| 14 | 13.5 | 48.5 | 32.0 |
Women's shoe sizing
| US | UK | EU | CM |
|---|---|---|---|
| 5 | 2.5 | 35 | 22.0 |
| 5.5 | 3 | 35.5 | 22.5 |
| 6 | 3.5 | 36 | 23.0 |
| 6.5 | 4 | 37 | 23.5 |
| 7 | 4.5 | 37.5 | 24.0 |
| 7.5 | 5 | 38 | 24.5 |
| 8 | 5.5 | 38.5 | 25.0 |
| 8.5 | 6 | 39 | 25.5 |
| 9 | 6.5 | 40 | 26.0 |
| 9.5 | 7 | 40.5 | 26.5 |
| 10 | 7.5 | 41 | 27.0 |
| 10.5 | 8 | 42 | 27.5 |
| 11 | 8.5 | 42.5 | 28.0 |
| 12 | 9.5 | 43.5 | 29.0 |
vs other brands
vs HOKA
On is narrower and lower to the ground; HOKA has a wider toe box and more stack.
vs Nike
Similar last shape and true-to-size behavior; On is slightly narrower.
Frequently asked questions
- Do On shoes run small?
- The lifestyle Cloud 5 and Cloud X do — size up 0.5. Performance running fits true to size but narrow.
Related
Reviewed against On Running's published size chart · Last updated June 2026