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 17.5026
Adult Medium 19.5029
Adult Large21.5030
Adult XL 2431
Adult 2XL25.5031
Adult 3XL 2834