Not sure about your shirt size? Follow these simple steps to figure it out:
Shoulder - Measure the shoulder at the back, from edge to edge with arms relaxed on both sides.
Chest - Measure around the body under the arms at the fullest part of the chest with your arms relaxed at both sides.
Sleeve - Measure from the shoulder seam through the outer arm to the cuff/hem.
Length - Measure from the highest point of the shoulder seam to the bottom hem of the garment's.