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 1727.50
Adult Medium 1928.50
Adult Large 2129
Adult XL 2230
Adult 2XL 2531
Adult 3XL 2732