It should be measured close to the body, preferably without clothing or in underwear.

A. Brust

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. 

C. Size

The waist is measured at the narrowest point.

D. Hip

The hip circumference is measured over the widest part of the hip.

E. Inseam

The inside leg length is measured between the crotch and the floor.