Chest: Measure from the bottom of one armpit seam across to the bottom of the other armpit seam. Double the number to get the actual chest size.
Body Length: Measure from the top of the neck seam to the bottom of the garment.
Shoulders: Measure from the top of the neck seam to the shoulder seam.
Sleeve Length: Measure from the shoulder seam to the bottom of the sleeve/cuff.