Step 1. Neck To measure the neck size, unbutton the shirt and spread the collar so it lays open and flat, then take a measurement from the button to buttonhole.

Step 2. Shoulder The shoulder measurement is taken by laying the shirt flat on its front and measuring the distance from the left shoulder seam up to the center yolk at the base of the collar and then down to the right shoulder seam.

Step 3. Chest The chest measurement is taken directly across the shirt 1 inch below the armhole.

Step 4. Waist The waist measurement is taken directly across the shirt 8 inches below the armhole.

Step 5. Bottom The bottom measurement is taken directly across the shirt at the base of the side seams.

Step 6. Length The length measurement is the distance straight down the back of the shirt from the base of the collar to the hem line.