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 Medium - Military Green1928.5
Adult Large - Military Green21.530.5
Adult XL - Military Green2332
Adult 2XL - Military Green2532.5