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 Small1727.50
Adult Medium1829
Adult Large20.5029
Adult XL22.5031
Adult 2XL23.5031
Adult 3XL24.5032