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 17.528
Adult Medium 2029
Adult Large 21.530.5
Adult XL 2430
Adult 2XL 2630.5
Adult 3XL 2832.5