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 - Light Blue Heather1828
Adult Medium - Light Blue Heather1928
Adult Large - Light Blue Heather21.530.5
Adult XL - Light Blue Heather23.531
Adult 2XL - Light Blue Heather2531.5