On Shoe Size Chart
What's my On size?
On Men's Size Chart
Enter your foot length to see your size highlighted here.
| US | EU | UK | JP / CM |
|---|---|---|---|
| 7 | 40 | 6.5 | 25 |
| 7.5 | 40.5 | 7 | 25.5 |
| 8 | 41 | 7.5 | 26 |
| 8.5 | 42 | 8 | 26.5 |
| 9 | 42.5 | 8.5 | 27 |
| 9.5 | 43 | 9 | 27.5 |
| 10 | 44 | 9.5 | 28 |
| 10.5 | 44.5 | 10 | 28.5 |
| 11 | 45 | 10.5 | 29 |
| 11.5 | 46 | 11 | 29.5 |
| 12 | 47 | 11.5 | 30 |
| 12.5 | 47.5 | 12 | 30.5 |
| 13 | 48 | 12.5 | 31 |
| 13.5 | 48.5 | 13 | 31.5 |
| 14 | 49 | 13.5 | 32 |
| 15 | 50 | 14.5 | 33 |
On Women's Size Chart
Enter your foot length to see your size highlighted here.
| US | EU | UK | JP / CM |
|---|---|---|---|
| 5 | 36 | 3 | 22 |
| 5.5 | 36.5 | 3.5 | 22.5 |
| 6 | 37 | 4 | 23 |
| 6.5 | 37.5 | 4.5 | 23.5 |
| 7 | 38 | 5 | 24 |
| 7.5 | 38.5 | 5.5 | 24.5 |
| 8 | 39 | 6 | 25 |
| 8.5 | 40 | 6.5 | 25.5 |
| 9 | 40.5 | 7 | 26 |
| 9.5 | 41 | 7.5 | 26.5 |
| 10 | 42 | 8 | 27 |
| 10.5 | 42.5 | 8.5 | 27.5 |
| 11 | 43 | 9 | 28 |
| 12 | 44 | 10 | 29 |
Data verified Aug 2026 · Official size guide · See an error? Report it
On Sizing & Fit Guide
On shoes run true to size but narrow. The Cloud 5 and Cloudmonster fit standard in length but snug in width. If you have wide feet, consider half a size up. No wide options available. On also sizes men's and women's on genuinely different EU/UK scales — a 25 cm foot is a women's EU 39 but a men's EU 40 — so match your own gender's row rather than assuming a shared conversion.
Frequently Asked Questions
On shoes run true to size but narrow. The Cloud 5 and Cloudmonster fit standard in length but snug in width. If you have wide feet, consider half a size up. No wide options available. On also sizes men's and women's on genuinely different EU/UK scales — a 25 cm foot is a women's EU 39 but a men's EU 40 — so match your own gender's row rather than assuming a shared conversion.
Enter your foot length in the finder at the top of this page — or, if you don't have a ruler, pick a brand you already know and your size in it — and we'll instantly highlight your equivalent On size in the men's and women's charts below. To compare your size across many brands at once, use our shoe size converter.
On EU 42 is approximately a US men's 8.5-9. However, exact conversions vary slightly. Use our size chart table above for the precise conversion, or try our interactive converter for personalized results.
The sizes above are On's own published men's and women's size guides, which run on genuinely different EU/UK scales — a 25 cm foot is a women's EU 39 but a men's EU 40. On shoes run true to size in length, so your usual US size is a safe starting point, but always check your own gender's chart above.
Yes — On shoes run true to size in length but fit narrow through the midfoot, especially on the Cloud 5 and Cloudmonster. On does not offer wide width options, so consider sizing up half a size if you have wide feet.