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 Green 1826.5
Adult Medium - Kelly Green 19.529.5
Adult Large - Kelly Green 2129.5
Adult XL - Kelly Green 22.530.5
Adult 2XL - Kelly Green 2531