THIS IS NOT YOUR AVERAGE LAB COAT.
  It's meant to be fitted with lots of stretch to allow for comfort. Order your size like its a blazer.  Measured in Inches: 
Sizes 38 40 42 44 46 48
Chest 37-38 39-40 41-42 43-44 45-46 47-48
Waist 30-32 32-34 34-36 36-38 38-40 40-42
Hip 37-38 39-40 41-42 43-44 45-46 47-48

 HOW TO MEASURE: 

CHEST: Measure across the fullest part of your chest

WAIST: Measure around your waist around your narrowest point

HIP: Measure around your fullest part of your hip.