On Running Shoe Size Guide
On Running uses a true-to-size length across the Cloud, Cloudmonster, Cloudsurfer and Cloudstratus families, with a snug, performance-oriented fit through the midfoot. If you are at the upper end of your size range or wear thick running socks, many runners size up half - especially in the road-running models.
Use the converter below to translate an On Running US size into UK, EU, JP, KR, CN, AU and MX. The reference charts further down show the full On Running women’s and men’s range side by side.
Convert a On Running shoe size
Pre-set to women’s US 8. Change the gender tab, system, or value to convert any On Running size.
| System | US / CA | UK | EU | AU | JP (cm) | KR (mm) | CN | MX | Foot (cm) | Foot (in) |
|---|---|---|---|---|---|---|---|---|---|---|
| Your size |
Sizes are approximate and may vary by brand. Check the manufacturer's size chart before buying.
On Running Women's Shoe Sizes
| US | UK | EU | JP | Foot (cm) |
|---|---|---|---|---|
| 4 | 2 | 34 | 21.0 | 21.0 |
| 4.5 | 2.5 | 34-35 | 21.5 | 21.3 |
| 5 | 3 | 35 | 22.0 | 21.6 |
| 5.5 | 3.5 | 35-36 | 22.5 | 22.0 |
| 6 | 4 | 36 | 23.0 | 22.5 |
| 6.5 | 4.5 | 36-37 | 23.5 | 22.9 |
| 7 | 5 | 37 | 23.5 | 23.3 |
| 7.5 | 5.5 | 37-38 | 24.0 | 23.7 |
| 8 | 6 | 38 | 24.5 | 24.1 |
| 8.5 | 6.5 | 38-39 | 25.0 | 24.5 |
| 9 | 7 | 39 | 25.5 | 25.0 |
| 9.5 | 7.5 | 39-40 | 26.0 | 25.4 |
| 10 | 8 | 40 | 26.0 | 25.9 |
| 10.5 | 8.5 | 40-41 | 26.5 | 26.2 |
| 11 | 9 | 41 | 27.0 | 26.7 |
| 11.5 | 9.5 | 41-42 | 27.5 | 27.1 |
| 12 | 10 | 42 | 28.0 | 27.6 |
On Running Men's Shoe Sizes
| US | UK | EU | JP | Foot (cm) |
|---|---|---|---|---|
| 6 | 5.5 | 38-39 | 24.0 | 23.5 |
| 6.5 | 6 | 39 | 24.5 | 23.8 |
| 7 | 6.5 | 39-40 | 25.0 | 24.1 |
| 7.5 | 7 | 40 | 25.0 | 24.5 |
| 8 | 7.5 | 40-41 | 25.5 | 25.0 |
| 8.5 | 8 | 41 | 26.0 | 25.4 |
| 9 | 8.5 | 41-42 | 26.5 | 25.7 |
| 9.5 | 9 | 42 | 27.0 | 26.0 |
| 10 | 9.5 | 42-43 | 27.0 | 26.5 |
| 10.5 | 10 | 43 | 27.5 | 27.0 |
| 11 | 10.5 | 43-44 | 28.0 | 27.3 |
| 11.5 | 11 | 44 | 28.5 | 27.9 |
| 12 | 11.5 | 44-45 | 29.0 | 28.3 |
| 12.5 | 12 | 45 | 29.5 | 28.6 |
| 13 | 12.5 | 45-46 | 30.0 | 29.2 |
| 14 | 13.5 | 47 | 31.0 | 30.0 |
| 15 | 14.5 | 48 | 32.0 | 30.8 |
Frequently asked questions
Do On Running shoes run true to size?
Yes - On Running’s men’s, women’s and kids’ ranges all fit true to size in length. The fit through the midfoot is snug and performance-oriented, which most runners prefer for road and tempo work but can feel tight if you are between sizes or wear thick socks.
Should I size up in On Cloud shoes?
For everyday use, your true size is correct. For long runs, hot weather or thick socks, sizing up half can give extra toe-box room and accommodate forefoot swelling. Cloudmonster and Cloudsurfer specifically have a slightly snugger upper, so half-size-up is more common there.
How do On Running sizes compare with Nike?
On Running and Nike use the same underlying US, UK and EU conversions. Fit is similar in length, but On’s midfoot is snugger than Nike’s Pegasus or Vomero. Most runners take their Nike size in On for everyday training and size up half for long-run models.
Sizes are approximate and may vary by On Running model. Always check the product-page size chart before buying.