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)