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 Blue17.527.5
Adult Medium - Light Blue2028
Adult Large - Light Blue21.530
Adult XL - Light Blue2430
Adult 2XL - Light Blue25.530.5