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 Green1727
Adult Medium - Kelly Green1927.5
Adult Large - Kelly Green2129
Adult XL - Kelly Green2329
Adult 2XL - Kelly Green2531