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 (6-8) - Baby Pink1620
Youth Medium (10-12) - Baby Pink1722.5
Youth Large (14-16) - Baby Pink17.524
Youth XS (2-4) - Baby Pink13.518