Birkenstock to New Balance shoe size
The short answer
Birkenstock 40 is New Balance 9 or 9.5 by the two brands' own charts.
At least one of the two brands publishes no foot length, so the rows line up the US size both charts print. Treat it as the label conversion, not a fit.
| Birkenstock | Birkenstock builds it for | New Balance, by chart | Same label | New Balance builds it for | New Balance also prints |
|---|---|---|---|---|---|
| 35 | not published | not made | not published | not published | not published |
| 36 | not published | 5 or 5.5 | not published | foot length 22 cm | US men's 3.5 · UK 3 · EU 35 |
| 37 | not published | 6 or 6.5 | not published | foot length 23 cm | US men's 4.5 · UK 4 · EU 36.5 |
| 38 | not published | 7 or 7.5 | not published | foot length 24 cm | US men's 5.5 · UK 5 · EU 37.5 |
| 39 | not published | 8 or 8.5 | not published | foot length 25 cm | US men's 6.5 · UK 6 · EU 39 |
| 40 | not published | 9 or 9.5 | not published | foot length 26 cm | US men's 7.5 · UK 7 · EU 40.5 |
| 41 | not published | 10 or 10.5 | not published | foot length 27 cm | US men's 8.5 · UK 8 · EU 41.5 |
| 42 | not published | 11 or 11.5 | not published | foot length 28 cm | US men's 9.5 · UK 9 · EU 43 |
| 43 | not published | 12 or 12.5 | not published | foot length 29 cm | US men's 10.5 · UK 10 · EU 44 |
| 44 | not published | 13 | not published | foot length 30 cm | US men's 11.5 · UK 11 · EU 45.5 |
| 48 | not published | not made | not published | not published | not published |
What wearers say
Charts describe a garment. People who own both brands describe a fit, and their answer ranks above this table once five of them stand behind it. Pick your size in the converter to see whether there are enough yet.
Sources
- Birkenstock size guide, read on 2026-09-18.
- New Balance size guide, read on 2026-09-17. New Balance on TrueToSize