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 - Kelly Green1726.75
Adult Medium - Kelly Green1929.25
Adult Large - Kelly Green20.529.75
Adult XL - Kelly Green21.530.5
Adult 2XL - Kelly Green2432.5