While there is significant variation in anatomical proportions between people, there are many references to body proportions that are intended to be canonical, either in art, measurement, or medicine.
In measurement, body proportions are often used to relate two or more measurements based on the body. A cubit, for instance, is supposed to be six palms. A span is taken to be 9 inches and was previously considered as half a cubit. While convenient, these ratios may not reflect the physiognomic variation of the individuals using them.
Similarly, in art, body proportions are the study of relation of human or animal body parts to each other and to the whole. These ratios are used in veristic depictions of the figure, and also become part of an aesthetic canon within a culture.
It is important in figure drawing to draw the human figure in proportion. Though there are subtle differences between individuals, human proportions fit within a fairly standard range, though artists have historically tried to create idealised standards, which have varied considerably over different periods and regions. In modern figure drawing, the basic unit of measurement is the 'head', which is the distance from the top of the head to the chin. This unit of measurement is reasonably standard, and has long been used by artists to establish the proportions of the human figure. Ancient Egyptian art used a canon of proportion based on the "fist", measured across the knuckles, with 18 fists from the ground to the hairline on the forehead. This was already established by the Narmer Palette from about the 31st century BC, and remained in use until at least the conquest by Alexander the Great some 3,000 years later.
The proportions used in figure drawing are:
A study using Polish participants by Sorokowski found 5% longer legs than an individual used as a reference was considered most attractive. The study concluded this preference might stem from the influence of leggy runway models. The Sorokowski study was criticized for using a picture of the same person with digitally altered leg lengths which Marco Bertamini felt were unrealistic.