Size Guide
Our sizes are expressed as the upper end of the age range for which a size is designed. As such, a size 6M is for babies between three and six months of age.
Please use a tape measure to determine the approximate measurement of your baby in Millie & Sebby clothing. In cases where a baby is in between sizes, go with the larger size.
| Size | Weight (lbs) | Height (in) | Weight (kg) | Height (cm) |
| NB | 6.0-9.0 | up to 21.5 | 2.7-4.1 | up to 54.6 |
| 3M | 9.0-12.5 | 21.5-24.0 | 4.1-5.7 | 54.6-61.0 |
| 6M | 12.5-17.0 | 24.0-26.5 | 5.7-7.7 | 61.0-67.3 |
| 9M | 17.0-21.0 | 26.5-28.5 | 7.7-9.5 | 67.3-72.4 |