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 Green17.526.5
Adult Medium - Kelly Green19.528
Adult Large - Kelly Green2129
Adult XL - Kelly Green2329.5
Adult 2XL - Kelly Green25.530.5
Adult Large - Kelly Green