On Shoe Size Chart
On runs true to size.
Runs SmallTrue to SizeRuns Large
On Men's Size Chart
| US | EU | UK | JP / CM |
|---|---|---|---|
| 4 | 36 | 3.5 | 22 |
| 4.5 | 36.5 | 4 | 22.5 |
| 5 | 37.5 | 4.5 | 23 |
| 5.5 | 38 | 5 | 23.5 |
| 6 | 38.5 | 5.5 | 24 |
| 6.5 | 39 | 6 | 24.5 |
| 7 | 40 | 6 | 25 |
| 7.5 | 40.5 | 6.5 | 25.5 |
| 8 | 41 | 7 | 26 |
| 8.5 | 42 | 7.5 | 26.5 |
| 9 | 42.5 | 8 | 27 |
| 9.5 | 43 | 8.5 | 27.5 |
| 10 | 44 | 9 | 28 |
| 10.5 | 44.5 | 9.5 | 28.5 |
| 11 | 45 | 10 | 29 |
| 11.5 | 45.5 | 10.5 | 29.5 |
| 12 | 46 | 11 | 30 |
| 13 | 47.5 | 12 | 31 |
| 14 | 48.5 | 13 | 32 |
On Women's Size Chart
| US | EU | UK | JP / CM |
|---|---|---|---|
| 5.5 | 36 | 3.5 | 22 |
| 6 | 36.5 | 4 | 22.5 |
| 6.5 | 37.5 | 4.5 | 23 |
| 7 | 38 | 5 | 23.5 |
| 7.5 | 38.5 | 5.5 | 24 |
| 8 | 39 | 6 | 24.5 |
| 8.5 | 40 | 6 | 25 |
| 9 | 40.5 | 6.5 | 25.5 |
| 9.5 | 41 | 7 | 26 |
| 10 | 42 | 7.5 | 26.5 |
| 10.5 | 42.5 | 8 | 27 |
| 11 | 43 | 8.5 | 27.5 |
| 11.5 | 44 | 9 | 28 |
| 12 | 44.5 | 9.5 | 28.5 |
| 12.5 | 45 | 10 | 29 |
| 13 | 45.5 | 10.5 | 29.5 |
| 13.5 | 46 | 11 | 30 |
| 14.5 | 47.5 | 12 | 31 |
| 15.5 | 48.5 | 13 | 32 |
Data verified Mar 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.
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.
Use the finder at the top of this page: pick the brand you already know and your size in it, and we'll show your equivalent On size instantly — and highlight it in the chart 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.