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 Green1927.5
Adult Large - Kelly Green22.528.5
Adult XL - Kelly Green23.531
Adult 2XL - Kelly Green25.531