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 - Royal Blue17.527
Adult Medium - Royal Blue1927.5
Adult XL - Royal Blue2329.5
Adult 2XL - Royal Blue2531