Length:(B) Measure from the highest point of the shoulder down to the bottom hem. This gives the full length of the hoodie.

Chest:(A) Measure around the fullest part of the chest, typically under the arms and across the shoulder blades. This determines the circumference of the chest area for the hoodie.

Sleeves:(C): Measure from the seam where the sleeve meets the body of the hoodie (the underarm seam), up to the end of the cuff. This measurement determines the length of the sleeve along the underside of the arm, from the armpit to the cuff.