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 17.527.5
Adult Medium 2030
Adult Large 21.531
Adult XL23.532
Adult 2XL2533.5
Adult 3XL2734.5