It should be measured close to the body, preferably without clothing or in underwear.
The chest circumference is measured over the widest part of the chest (with bra).
B. Under bust size
The underbust measurement is measured directly below the bust.
The waist is measured at the narrowest point.
The hip circumference is measured over the widest part of the hip.
The inside leg length is measured between the crotch and the floor.