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)
Girls Small (6/7) - Banana Yellow1219
Girls Medium (8-10) - Banana Yellow13.521
Girls Large (12-14) - Banana Yellow14.522.5
Girls XL (16) - Banana Yellow16.524.5