3 month 6 months 9 months 12 months 24 months 
Height 19" - 23" 23" - 25" 25" - 27" 27" - 29" 31" - 33"
Weight 7 - 12 lbs 12 - 17 lbs 17 - 20 lbs 20 - 22 lbs 27 - 30 lbs
Chest 16.5" 17.5" 18.125" 18.5" 20"
Waist 17" 17.75" 18.5" 19" 20.25"
Hip 17" 18" 19" 19.25" 20.25"
Inseam 6.75" 8" 8.625" 9.25" 11.75"
Head 16.5" 17.5" 18" 18.5" 19.5"

Graphic describing size chart references