How to measure
Chest
Measure at 1" below the underarm on the side seam, straight across chest from edge to edge.
Body length
Measure from the high point of shoulder seam, at the edge of the neckline, all the way down to the bottom hem of the shirt.
Sleeve length
Measure from the high point of shoulder seam, at the edge of the neckline, along the shoulder seam to the open hem of the sleeve.