Measurements refer to body size not garment dimensions.
Choosing the right size
(1): Measure the chest under the arms around the fullest point.
(2): Measure at the smallest part of the waist, often at or above the belly button, below the ribs.
(3): Measure the hip circumference at the fullest part of the seat.
(4): Measure the distance from the prominent bone on the spine at the neck, across the shoulder, over the bent elbow to the center of the wrist bone.
(5): Measure the distance from the crotch point to the bottom of the ankle.