This image demonstrates the blend of mathematics and art during the Renaissance and demonstrates Leonardo's deep understanding of proportion.
In addition, this picture represents a cornerstone of Leonardo's attempts to relate man to nature.
Encyclopædia Britannica online states, "Leonardo envisaged the great picture chart of the human body he had produced through his anatomical drawings and Vitruvian Man as a cosmografia del minor mondo (cosmography of the microcosm).
He believed the workings of the human body to be an analogy for the workings of the universe."

According to Leonardo's preview in the accompanying text, written in mirror writing, it was made as a study of the proportions of the (male) human body as described in Vitruvius' De architectura 3.1.2–3, which reads:
For the human body is so designed by nature that the face, from the chin to the top of the forehead and the lowest roots of the hair, is a tenth part of the whole height; the open hand from the wrist to the tip of the middle finger is just the same; the head from the chin to the crown is an eighth, and with the neck and shoulder from the top of the breast to the lowest roots of the hair is a sixth; from the middle of the breast to the summit of the crown is a fourth.
If we take the height of the face itself, the distance from the bottom of the chin to the under side of the nostrils is one third of it; the nose from the under side of the nostrils to a line between the eyebrows is the same; from there to the lowest roots of the hair is also a third, comprising the forehead.
The length of the foot is one sixth of the height of the body; of the forearm, one fourth; and the breadth of the breast is also one fourth.
The other members, too, have their own symmetrical proportions, and it was by employing them that the famous painters and sculptors of antiquity attained to great and endless renown.

Similarly, in the members of a temple there ought to be the greatest harmony in the symmetrical relations of the different parts to the general magnitude of the whole.
Then again, in the human body the central point is naturally the navel.
For if a man be placed flat on his back, with his hands and feet extended, and a pair of compasses centred at his navel, the fingers and toes of his two hands and feet will touch the circumference of a circle described therefrom.
And just as the human body yields a circular outline, so too a square figure may be found from it.
For if we measure the distance from the soles of the feet to the top of the head, and then apply that measure to the outstretched arms, the breadth will be found to be the same as the height, as in the case of plane surfaces which are perfectly square.

Yet, while Leonardo shows direct knowledge of Vitruvius, his drawing does not follow the description of the ancient text.
In drawing the circle and square he observes that the square cannot have the same centre as the circle, but is centered at the groin.
This adjustment is the innovative part of Leonardo's drawing and what distinguishes it from earlier illustrations.
He also departs from Vitruvius by drawing the arms raised to a position in which the fingertips are level with the top of the head, rather than Vitruvius's much lower angle, in which the arms form lines passing through the navel.

It may be noticed by examining the drawing that the combination of arm and leg positions creates sixteen different poses.
The pose with the arms straight out and the feet together is seen to be inscribed in the superimposed square.
On the other hand, the spread-eagle pose is seen to be inscribed in the superimposed circle.

Leonardo's collaboration with Luca Pacioli, the author of Divina proportione (Divine Proportion) have led some to speculate that he incorporated the golden ratio in Vitruvian Man, but this is not supported by any of Leonardo's writings, and its proportions do not match the golden ratio precisely.
Vitruvian Man is likely to have been drawn before Leonardo met Pacioli.
This image demonstrates the blend of mathematics and art during the Renaissance and demonstrates Leonardo's deep understanding of proportion. In addition, this picture represents a cornerstone of Leonardo's attempts to relate man to nature. Encyclopædia Britannica online states, "Leonardo envisaged the great picture chart of the human body he had produced through his anatomical drawings and Vitruvian Man as a cosmografia del minor mondo (cosmography of the microcosm). He believed the workings of the human body to be an analogy for the workings of the universe."
According to Leonardo's preview in the accompanying text, written in mirror writing, it was made as a study of the proportions of the (male) human body as described in Vitruvius' De architectura 3.1.2–3, which reads:
For the human body is so designed by nature that the face, from the chin to the top of the forehead and the lowest roots of the hair, is a tenth part of the whole height; the open hand from the wrist to the tip of the middle finger is just the same; the head from the chin to the crown is an eighth, and with the neck and shoulder from the top of the breast to the lowest roots of the hair is a sixth; from the middle of the breast to the summit of the crown is a fourth. If we take the height of the face itself, the distance from the bottom of the chin to the under side of the nostrils is one third of it; the nose from the under side of the nostrils to a line between the eyebrows is the same; from there to the lowest roots of the hair is also a third, comprising the forehead. The length of the foot is one sixth of the height of the body; of the forearm, one fourth; and the breadth of the breast is also one fourth. The other members, too, have their own symmetrical proportions, and it was by employing them that the famous painters and sculptors of antiquity attained to great and endless renown.
Similarly, in the members of a temple there ought to be the greatest harmony in the symmetrical relations of the different parts to the general magnitude of the whole. Then again, in the human body the central point is naturally the navel. For if a man be placed flat on his back, with his hands and feet extended, and a pair of compasses centred at his navel, the fingers and toes of his two hands and feet will touch the circumference of a circle described therefrom. And just as the human body yields a circular outline, so too a square figure may be found from it. For if we measure the distance from the soles of the feet to the top of the head, and then apply that measure to the outstretched arms, the breadth will be found to be the same as the height, as in the case of plane surfaces which are perfectly square.
Yet, while Leonardo shows direct knowledge of Vitruvius, his drawing does not follow the description of the ancient text. In drawing the circle and square he observes that the square cannot have the same centre as the circle, but is centered at the groin. This adjustment is the innovative part of Leonardo's drawing and what distinguishes it from earlier illustrations. He also departs from Vitruvius by drawing the arms raised to a position in which the fingertips are level with the top of the head, rather than Vitruvius's much lower angle, in which the arms form lines passing through the navel.
It may be noticed by examining the drawing that the combination of arm and leg positions creates sixteen different poses. The pose with the arms straight out and the feet together is seen to be inscribed in the superimposed square. On the other hand, the spread-eagle pose is seen to be inscribed in the superimposed circle.
Leonardo's collaboration with Luca Pacioli, the author of Divina proportione (Divine Proportion) have led some to speculate that he incorporated the golden ratio in Vitruvian Man, but this is not supported by any of Leonardo's writings, and its proportions do not match the golden ratio precisely. Vitruvian Man is likely to have been drawn before Leonardo met Pacioli.
Vitruvian Man