Neck
Measure around the lower part of your neck, placing one finger between tape measure and neck.
Shoulders
Measure from one edge of the shoulder to the other, across back.
Chest
Measure around the fullest part of the chest, do not puff up chest
Waist
Measure around your waistline where your belly button is. Keep a finger between your body and the measuring tape for an accurate fit.
Sleeves
With your arm remaining straight at your side, measure from the shoulder seam of your shirt down to your wrist and add one more inch for allowance.