Manufacturers Size Guide Chart:
Infant Size Chart
Size
Height
Weight
XS (0-6 Months)
Up to 26"
Up to 16 lbs
S (6-12 Months)
26 - 29.5"
16 - 23 lbs
M (12-18 Months)
29.5 - 32"
23 - 27 lbs
L (18 Months - 2T)
33 - 35"
27 - 30 lbs