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 1927
Adult Large 2127.50
Adult XL 2328.50
Adult 2XL 2529.50
Adult 3XL 2730.50