This fit pointer will help you to find the best fit and style, based on the measurement of a garment that already sits on the body correctly. All measurements taken from the outside of the garment, with the garment lying flat:
Chest circumference: With buttons fastened, measure the width of the shirt from the underarm seam and double.
Waist circumference: With buttons fastened, measure the width of the shirt exactly 8 inches below the lowest point of the underarm, and double.
Back length: The length at the centre back from the base of the collar to the hem.
Sleeve length: Measure from the shoulder seam to the end of the cuff.
Bicep: Measure the width of the sleeve from the underarm seam and double.