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 - Red 1826.5
Adult Medium - Red 19.528
Adult Large - Red 2229
Adult XL - Red 2330
Adult 2XL - Red 25.530.5