THE MARC JACOBS Baby sizes 1 - 18 month
| Approximate age | Child's height |
| 1 month | 54 cm |
| 3 month | 60 cm |
| 6 month | 67 cm |
| 9 month | 71 cm |
| 12 month | 74 cm |
| 18 month | 81 cm |
THE MARC JACOBS Junior sizes 2 - 14 years
| Approximate age | Child's height |
| 2 year | 86 cm |
| 3 year | 94 cm |
| 4 year | 102 cm |
| 5 year | 108 cm |
| 6 year | 114 cm |
| 8 year | 126 cm |
| 10 year | 138 cm |
| 12 year | 150 cm |
| 12+ / 14 year | 156 cm |
THE MARRC JACOBS pre-walker shoes sizes
 EU |  UK |  USA | Approximate age |
| 16-17 | 0-1 | 1-2 | 3-6 month |
| 18-19 | 2-3 | 3-4 | 9-12 month |
THE MARC JACOBS shoes sizes
| EU | UK | USA |
| 23 | 6 | 6.5 |
| 24 | 7 | 7.5 |
| 25 | 7.5 | 8 |
| 26 | 8.5 | 9.5 |
| 27 | 9 | 10.5 |
| 28 | 10 | 11 |
| 29 | 11 | 12 |
| 30 | 11.5 | 12.5 |
| 31 | 12.5 | 13 |
| 32 | 13 | 1.5 |
| 33 | 1 | 2 |
| 34 | 2 | 3 |
| 35 | 2.5 | 3.5 |
| 36 | 3.5 | 4.5 |
| 37 | 4 | 5 |
| 38 | 5 | 6 |
| 39 | 6 | 7 |