Children's clothing size 90 is between 26-28 inches (66 to 71.1 cm) in height.

Size conversion chart for tops or T-shirt

International size conversion chart for pants, jeans, bottom

Children’s US size to height and weight measurement

Baby (Preemie, 0-24 months)

Toddler  (2T-6T)

Little Kid  (4-6X)

Big Kid or Tween  (7-16)