Fits are measured on the body and not on the clothes. Fits may vary by personal preference.
Bust
Measure around the fullest part, with your arms down by your side, slightly apart.
Waist
Measure around your natural waist above the hips*.
Hips
Measure 20cm down from the natural waist (9cm down if you
are 'Petite').
* Your tape measure must be horizontal at all times.