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) - Silver1219.5
Girls Medium (8-10) - Silver12.520
Girls Large (12-14) - Silver14.522.5
Girls XL (16) - Silver1625.5
Girls 4 - Silver11.518
Girls 5-6 - Silver1219.5
Girls 6X - Silver12.520