Altra Shoe Size Chart
Altra's own published size chart, matched to real measured foot length. Measure your foot once and read your Altra size directly from the table below — or use the shoe size calculator to do it for you and compare against 34 other brands.
Altra men's size chart
| Foot length (cm) | US | UK | EU | JP |
|---|---|---|---|---|
| 22 | 4 | 3 | 37 | 22 |
| 22.5 | 4.5 | 3.5 | 37.5 | 22.5 |
| 23 | 5 | 4 | 38 | 23 |
| 23.5 | 5.5 | 4.5 | 38.5 | 23.5 |
| 24 | 6 | 5 | 39 | 24 |
| 24.5 | 6.5 | 5.5 | 39.5 | 24.5 |
| 25 | 7 | 6 | 40 | 25 |
| 25.5 | 7.5 | 6.5 | 40.5 | 25.5 |
| 26 | 8 | 7 | 41 | 26 |
| 26.5 | 8.5 | 7.5 | 42 | 26.5 |
| 27 | 9 | 8 | 42.5 | 27 |
| 27.5 | 9.5 | 8.5 | 43 | 27.5 |
| 28 | 10 | 9 | 44 | 28 |
| 28.5 | 10.5 | 9.5 | 44.5 | 28.5 |
| 29 | 11 | 10 | 45 | 29 |
| 29.5 | 11.5 | 10.5 | 46 | 29.5 |
| 30 | 12 | 11 | 46.5 | 30 |
| 30.5 | 12.5 | 11.5 | 47 | 30.5 |
| 31 | 13 | 12 | 48 | 31 |
| 32 | 14 | 13 | 49 | 32 |
| 33 | 15 | 14 | 50 | 33 |
| 34 | 16 | 15 | 51.5 | 34 |
Altra women's size chart
| Foot length (cm) | US | UK | EU | JP |
|---|---|---|---|---|
| 20.5 | 4 | 2 | 34.5 | 20.5 |
| 21 | 4.5 | 2.5 | 35 | 21 |
| 21.5 | 5 | 3 | 35.5 | 21.5 |
| 22 | 5.5 | 3.5 | 36 | 22 |
| 22.5 | 6 | 4 | 37 | 22.5 |
| 23 | 6.5 | 4.5 | 37.5 | 23 |
| 23.5 | 7 | 5 | 38 | 23.5 |
| 24 | 7.5 | 5.5 | 38.5 | 24 |
| 24.5 | 8 | 6 | 39 | 24.5 |
| 25 | 8.5 | 6.5 | 40 | 25 |
| 25.5 | 9 | 7 | 40.5 | 25.5 |
| 26 | 9.5 | 7.5 | 41 | 26 |
| 26.5 | 10 | 8 | 42 | 26.5 |
| 27 | 10.5 | 8.5 | 42.5 | 27 |
| 27.5 | 11 | 9 | 43 | 27.5 |
| 28 | 11.5 | 9.5 | 44 | 28 |
| 28.5 | 12 | 10 | 44.5 | 28.5 |
| 29.5 | 13 | 11 | 46 | 29.5 |
Altra kids' size chart
| Foot length (cm) | US | UK | EU | JP |
|---|---|---|---|---|
| 19 | 13 | K12 | 32 | 19 |
| 20 | 1 | K13 | 32.5 | 20 |
| 20.5 | 1.5 | K14 | 33 | 20.5 |
| 21 | 2 | 1 | — | 21 |
| 21.5 | 2.5 | 1.5 | 34.5 | 21.5 |
| 22 | 3 | 2 | 35 | 22 |
| 22.5 | 3.5 | 2.5 | 35.5 | 22.5 |
| 23 | 4.5 | 3.5 | 37 | 23 |
| 23.5 | 5 | 4 | 37.5 | 23.5 |
| 24 | 5.5 | 4.5 | 38 | 24 |
| 24.5 | 6 | 5 | 39 | 24.5 |
How to measure for Altra
Measure heel-to-toe standing, using the longer foot. IMPORTANT -- Altra's own sizing instructions tell you to ADD 0.5cm to your measured foot length before reading their chart, to allow room for your toes to splay in their wider FootShape toe box. The figures here are Altra's published chart values as-is, so if you want to follow Altra's own guidance, add 0.5cm to your measurement before entering it, or simply take the next half size up from the result shown.
Altra fit guidance
Altra is built around two features that set it apart: a zero-drop platform (heel and forefoot at the same height) and a foot-shaped 'FootShape' toe box that is noticeably wider at the toes than a conventional last. If you are coming from a traditional running shoe, the extra toe room is normal and intended, not a sign the shoe is too big -- but see the measurement note above about Altra's own recommendation to allow an extra 0.5cm. Altra's youth range runs roughly a 19cm to 24.5cm foot. Two quirks in Altra's own published youth chart are worth knowing: it lists both a 3.5 and a 4 at 22.5cm, so those two sizes are the same length in their table, and its EU column runs out of sequence at US 2 — that EU value is omitted here rather than guessed. Note also that Altra's adult advice to add 0.5cm before reading the chart is not repeated on their youth chart.
Where this data comes from
- Altra Footwear & Apparel Sizing Guide (official)
- Altra Running Size Guide, incl. +0.5cm instruction (official EU)
- Altra size chart (Marathon Sports)
- Altra Youth Size Chart (official)
Sizing information reviewed September 2026. Manufacturers revise their charts from time to time — always confirm against the specific model before buying.
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