Allbirds to Onitsuka Tiger shoe size
The short answer
Allbirds 8.5 is Onitsuka Tiger 25 or 25.5 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.
| Allbirds | Allbirds builds it for | Onitsuka Tiger, by chart | Same label | Onitsuka Tiger builds it for | Onitsuka Tiger also prints |
|---|---|---|---|---|---|
| 5 | not published | 22 or 22.5 | not published | not published | US women's 4.5 · US men's 3 · UK 2 · EU 35 |
| 5.5 | not published | 22.5 | not published | not published | US women's 5.5 · US men's 4 · UK 3 · EU 35.5 |
| 6 | not published | 23 | not published | not published | US women's 6 · US men's 4.5 · UK 3.5 · EU 37 |
| 6.5 | not published | 23.5 | not published | not published | US women's 6.5 · US men's 5 · UK 4 · EU 37.5 |
| 7 | not published | 24 | not published | not published | US women's 7 · US men's 5.5 · UK 4.5 · EU 38 |
| 7.5 | not published | 24.5 | not published | not published | US women's 7.5 · US men's 6 · UK 5 · EU 39 |
| 8 | not published | 25 | not published | not published | US women's 8 · US men's 6.5 · UK 5.5 · EU 39.5 |
| 8.5 | not published | 25 or 25.5 | not published | not published | US women's 8 · US men's 6.5 · UK 5.5 · EU 39.5 |
| 9 | not published | 25.5 | not published | not published | US women's 9 · US men's 7.5 · UK 6.5 · EU 40 |
| 9.5 | not published | 26 | not published | not published | US women's 9.5 · US men's 8 · UK 7 · EU 41.5 |
| 10 | not published | 26.5 | not published | not published | US women's 10 · US men's 8.5 · UK 7.5 · EU 42 |
| 10.5 | not published | 27 | not published | not published | US women's 10.5 · US men's 9 · UK 8 · EU 42.5 |
| 11 | not published | 27.5 | not published | not published | US women's 11 · US men's 9.5 · UK 8.5 · EU 43.5 |
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
- Allbirds size guide, read on 2026-09-18. Allbirds on TrueToSize
- Onitsuka Tiger size guide, read on 2026-09-18. Onitsuka Tiger on TrueToSize