Lay your current hoodie or sweatshirt flat on a hard surface with the front of the hoodie facing up,
Place the measuring tape at the seam where the collar band attaches to the sleeve and measure straight down the middle of the front of the hoodie to the hem at its longest point.
Body Width
Lay your current hoodie or sweatshirt flat on a hard surface,
Find the widest part of the hoodie, which should be between the armpits of the hoodie,
Measure straight across from the left of the hoodie to the right of the hoodie.
If in doubt, or in-between sizes, choose bigger size!