Size Guide — Altra Size Guide
Altra Signature FootShape™ Fits
Every Altra is built on our FootShape™ last so your toes can relax and spread out naturally. Within that, we offer four fit profiles to suit different foot shapes:
- Original: The fit that started it all. Our most generous option, with the highest volume and maximum room for natural toe splay.
Standard: Our most common fit. Designed for a secure midfoot lockdown while still giving the forefoot room to breathe.
Slim: A closer-to-foot feel for narrower foot profiles, without sacrificing the space your toes need to function.
Wide: Even more room through the midfoot and forefoot. Built on a 2E last for men and a D last for women.
How to Measure Your Foot
- Stand on a piece of paper with your heel flat against a wall.
- Mark the tip of your longest toe (this isn't always your big toe).
- Measure from the wall to the mark in centimetres.
- Match the measurement to your size in the table below.
- We recommend leaving roughly 1 cm to 1.5 cm of room at the front of the shoe to allow for natural foot expansion during your run.
Men's Shoe Size Chart
Your usual AU men's size matches the UK system. Altra ships in US sizes — that's the size you'll order.
| US | UK | AU | EU | CM | |
|---|---|---|---|---|---|
| 4 | 4 | 3 | 3 | 37 | 22 |
| 4.5 | 4.5 | 3.5 | 3.5 | 37.5 | 22.5 |
| 5 | 5 | 4 | 4 | 38 | 23 |
| 5.5 | 5.5 | 4.5 | 4.5 | 38.5 | 23.5 |
| 6 | 6 | 5 | 5 | 39 | 24 |
| 6.5 | 6.5 | 5.5 | 5.5 | 39.5 | 24.5 |
| 7 | 7 | 6 | 6 | 40 | 25 |
| 7.5 | 7.5 | 6.5 | 6.5 | 40.5 | 25.5 |
| 8 | 8 | 7 | 7 | 41 | 26 |
| 8.5 | 8.5 | 7.5 | 7.5 | 42 | 26.5 |
| 9 | 9 | 8 | 8 | 42.5 | 27 |
| 9.5 | 9.5 | 8.5 | 8.5 | 43 | 27.5 |
| 10 | 10 | 9 | 9 | 44 | 28 |
| 10.5 | 10.5 | 9.5 | 9.5 | 44.5 | 28.5 |
| 11 | 11 | 10 | 10 | 45 | 29 |
| 11.5 | 11.5 | 10.5 | 10.5 | 46 | 29.5 |
| 12 | 12 | 11 | 11 | 46.5 | 30 |
| 12.5 | 12.5 | 11.5 | 11.5 | 47 | 30.5 |
| 13 | 13 | 12 | 12 | 48 | 31 |
| 14 | 14 | 13 | 13 | 49 | 32 |
| 15 | 15 | 14 | 14 | 50 | 33 |
| 16 | 16 | 15 | 15 | 51.5 | 34 |
Women's Shoe Size Chart
Your usual AU women's size matches the US system. Altra ships in US sizes — same number, no conversion needed.
| US | UK | AU | EU | CM | |
|---|---|---|---|---|---|
| 4 | 4 | 2 | 4 | 34.5 | 20.5 |
| 4.5 | 4.5 | 2.5 | 4.5 | 35 | 21 |
| 5 | 5 | 3 | 5 | 35.5 | 21.5 |
| 5.5 | 5.5 | 3.5 | 5.5 | 36 | 22 |
| 6 | 6 | 4 | 6 | 37 | 22.5 |
| 6.5 | 6.5 | 4.5 | 6.5 | 37.5 | 23 |
| 7 | 7 | 5 | 7 | 38 | 23.5 |
| 7.5 | 7.5 | 5.5 | 7.5 | 38.5 | 24 |
| 8 | 8 | 6 | 8 | 39 | 24.5 |
| 8.5 | 8.5 | 6.5 | 8.5 | 40 | 25 |
| 9 | 9 | 7 | 9 | 40.5 | 25.5 |
| 9.5 | 9.5 | 7.5 | 9.5 | 41 | 26 |
| 10 | 10 | 8 | 10 | 42 | 26.5 |
| 10.5 | 10.5 | 8.5 | 10.5 | 42.5 | 27 |
| 11 | 11 | 9 | 11 | 43 | 27.5 |
| 11.5 | 11.5 | 9.5 | 11.5 | 44 | 28 |
| 12 | 12 | 10 | 12 | 44.5 | 28.5 |
| 13 | 13 | 11 | 13 | 46 | 29.5 |