Altra is an American brand that runs relatively small. If you're unsure, you can also check the US size of your current shoes for comparison.
For the most accurate measurement, make sure to measure your feet at the end of the day, as they can swell towards the end of the day.
Size chart Altra Men and Women
| CM | EU | UK | US | UK | US |
| M/F | M | M | V | V | |
| 22 | 36 | 3.5 | 5.5 | ||
| 22.5 | 37 | 4 | 6 | ||
| 23 | 37.5 | 4.5 | 6.5 | ||
| 23.5 | 38 | 5 | 7 | ||
| 24 | 38.5 | 5.5 | 7.5 | ||
| 24.5 | 39 | 6 | 8 | ||
| 25 | 40 | 6 | 7 | 6.5 | 8.5 |
| 25.5 | 40.5 | 6.5 | 7.5 | 7 | 9 |
| 26 | 41 | 7 | 8 | 7.5 | 9.5 |
| 26.5 | 42 | 7.5 | 8.5 | 8 | 10 |
| 27 | 42.5 | 8 | 9 | 8.5 | 10.5 |
| 27.5 | 43 | 8.5 | 9.5 | 9 | 11 |
| 28 | 44 | 9 | 10 | 9.5 | 11.5 |
| 28.5 | 44.5 | 9.5 | 10.5 | 10 | 12 |
| 29 | 45 | 10 | 11 | ||
| 29.5 | 46 | 10.5 | 11.5 | ||
| 30 | 46.5 | 11 | 12 | ||
| 30.5 | 47 | 11.5 | 12.5 | ||
| 31 | 48 | 12 | 13 | ||
| 32 | 49 | 13 | 14 | ||
| 33 | 50 | 14 | 15 | ||
| 34 | 51.5 | 15 | 16 |
