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 Blue17.526.5
Adult Medium - Light Blue2029
Adult Large - Light Blue20.528.5
Adult XL - Light Blue23.531.5
Adult 2XL - Light Blue2530.5