YOUTH UNISEX T-SHIRT SIZES: (Inches)
Size Length Chest
S 20 ⅞ 28 - 32
M 22 ⅛ 32 - 36
L 23 ⅜ 36 - 38
XL 24 ⅜ 38 - 40

Product measurements may vary by up to 2". 
Pro Tip: Measure one of your child's t-shirts at home and compare it with the measurements you see in this guide.