To find your correct size, use a tape measure and take these measurements. Stand with your back straight in front of a mirror, to make sure that you measure correctly and that the tape measure is kept level.
Measure under your armpits, around your shoulder blades, and over the fullest part of your bust. Don't pull the tape measure too hard.
Measure around your natural waistline. This is the narrow part of your waist, above your navel. Relax and breath out before you measure.
The hip should be measured around its fullest part.