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)
Junior Small - Light Silver1525.5
Junior Medium - Light Silver16.527
Junior Large - Light Silver1727.5
Junior XL - Light Silver1726.5