The two main body measurements you can use are Chest (for tops) and Waist (for bottoms).
Please take your body measurements.
Chest Circumference: take the measurement around the fullest part of your chest, ensuring that you keep the tape level over the shoulder blades and close up under the arms.
Waist Circumference: measure around the narrowest part of the waistline, at the height where you would wear your pants or shorts.
You can then use these measurements to find our size on our body measurements charts. https://www.nblstore.com.au/pages/size-guide