Width is measured across the chest below the sleeves from seam to seam. Height is measured from the bottom of the shirt to the highest point on the shoulder (where the seam meets the neck).

Please note that each product has its own specific sizing chart.
SizeWidth (inches)Height (inches)
Toddler 2T - Red1114.5
Toddler 3T - Red11.515.5
Toddler 4T - Red1216
Infant 12M - Red10
Infant 18M - Red10.513.5
Infant 24M - Red1114