How to measure:
Wearing a non-padded bra, take a soft tape measure under your arms, across the shoulder blades at the back and around the fullest part of your bust at front. The tape measure should fit comfortably (not too tight) and sit parallel to the floor.
Bend to one side to find natural indentation in the torso. This is your natural waist. Run tape around the natural waistline, keeping it level with the floor.
Stand on a level surface with your feet together. Measure around the fullest part of the hips (approximately 7-9" below waistline), keeping tape level with the floor.