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)
Youth Small (5-6) - Navy Blue15.520
Youth Medium (7-8) - Navy Blue16.522.5
Youth Large (10-12) - Navy Blue17.523.5
Youth XL (14-16) - Navy Blue18.524.5