| Birkenstock Adults | |||||
| US/AUS | UK | EU | Length (mm) | Width (mm) | |
| Womens (Regular Width) | |||||
| 4-4.5 | 35 | 225mm | 89mm | ||
| 5-5.5 | 36 | 230mm | 91mm | ||
| 6-6.5 | 37 | 240mm | 93mm | ||
| 7-7.5 | 38 | 245mm | 95mm | ||
| 8-8.5 | 39 | 250mm | 97mm | ||
| 9-9.5 | 40 | 260mm | 99mm | ||
| 10-10.5 | 41 | 265mm | 101mm | ||
| 11-11.5 | 42 | 270mm | 102mm | ||
| Womens (Narrow Width) | |||||
| 4-4.5 | 35 | 225mm | 85mm | ||
| 5-5.5 | 36 | 230mm | 87mm | ||
| 6-6.5 | 37 | 240mm | 89mm | ||
| 7-7.5 | 38 | 245mm | 91mm | ||
| 8-8.5 | 39 | 250mm | 93mm | ||
| 9-9.5 | 40 | 260mm | 95mm | ||
| 10-10.5 | 41 | 265mm | 97mm | ||
| 11-11.5 | 42 | 270mm | 99mm | ||
| Mens (Regular Width) | |||||
| 7-7.5 | 40 | 260mm | 99mm | ||
| 8-8.5 | 41 | 265mm | 101mm | ||
| 9-9.5 | 42 | 270mm | 102mm | ||
| 10-10.5 | 43 | 280mm | 103mm | ||
| 11-11.5 | 44 | 285mm | 107mm | ||
| 12-12.5 | 45 | 290mm | 109mm | ||
| 13-13.5 | 46 | 300mm | 113mm | ||
| 14-14.5 | 47 | 305mm | 115mm | ||
| Mens (Narrow Width) | |||||
| 7-7.5 | 40 | 260mm | 95mm | ||
| 8-8.5 | 41 | 265mm | 97mm | ||
| 9-9.5 | 42 | 270mm | 99mm | ||
| 10-10.5 | 43 | 280mm | 101mm | ||
| 11-11.5 | 44 | 285mm | 103mm | ||
| 12-12.5 | 45 | 290mm | 105mm | ||
| 13-13.5 | 46 | 300mm | 107mm | ||
| 14-14.5 | 47 | 305mm | 109mm | ||
| Birkenstock Kids | |||
| US/AUS | EU | Length | Width |
| 6-6.5 | 24 Narrow | 150mm | 63mm |
| 7-7.5 | 25 Narrow | 160mm | 65mm |
| 8-8.5 | 26 Narrow | 165mm | 67mm |
| 9-9.5 | 27 Narrow | 170mm | 69mm |
| 10-10.5 | 28 Narrow | 180mm | 71mm |
| 11-11.5 | 29 Narrow | 185mm | 73mm |
| 12-12.5 | 30 Narrow | 190mm | 75mm |
| 13-13.5 | 31 Narrow | 200mm | 77mm |
| 1-1.5 | 32 Narrow | 205mm | 79mm |
| 2-2.5 | 33 Narrow | 210mm | 81mm |
| 3-3.5 | 34 Narrow | 220mm | 83mm |
