Measurements are taken with the garment laid flat.
Chest is measured 2.5cm below armpit straight across the front.
Front length is measured from the seam where the shoulder meets the collar straight down the front to the bottom of the hem. Back length is measured from the seam where the shoulder meets the collar straight down the back to the bottom of the hem. Shoulder to shoulder is from the seam of the shoulder straight across the back to the other shoulder seam.