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)
Adult Small - Light Navy1826.5
Adult Medium - Light Navy19.528
Adult Large - Light Navy2129
Adult XL - Light Navy2429.5
Adult 2XL - Light Navy25.531