How to measure?
Little seamstress advice:
Heat your measuring tape in your hands.
Measure your chest circumference as strongly as possible, supple and on a soft bra if possible.
Take your turn under the birth of the breasts, tightening slightly the measuring tape.
Take the measure in the hollow of your size: this measurement is random and moves a lot.
If in doubt, refer to the measurement of the hips.
Measure at the fold of your legs and at the height of your buttocks.