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 Size 4 - Charcoal1418
Youth Size 5/6 - Charcoal1519.5
Youth Size 7/8 - Charcoal1621.5
Youth Size 10/12 - Charcoal17.524
Youth Size 14 - Charcoal1825.5