A 10 head figure is the illustrating
standard (as of the early 2000's) for fashion
drawings. The figures are, obviously, 10 times as tall as their heads. They're horribly distorted figures, as the average human
is between 6 and 7 heads tall. If, however, you're into drawing obscenely proportioned figures, the formula is below.
Draw a vertical line 12-15 inches tall, and divide the line into 10 vertical partitions, evenly spaced. The top partition is the head, and the chin falls directly at the bottom of the line. The shoulders should be placed in the very center of the 2nd head, and the distance between (roughly half a head's length) is the neck.
For drawing the torso, place the waist in the middle of the 4th partition, and the hips (and crotch) at the split between the 4th and 5th segment. This should be the widest portion of the torso. The bust should be halfway between the shoulders and waist, and if you wish the torso to be curved, you should lay a movement line over the center line to form the torso around.
For the legs, the easiest method is to place where you wish the feet to be in the finished drawing. A straight leg will end (foot included) at the very bottom of the center line. One leg should be kept straight along the line as a supporting leg, and the other can be placed as you desire. Just remember that the knee is properly placed just above the middle of the leg, about 2/3rds the way down the 6th segment.
Perverse, yes, but the way things are done in the industry.
Now, if only I could find a woman with those proportions...