The cranial index is an anthropometric measurement used to classify the shape of the human skull based on the ratio of its maximum breadth to its maximum length. It was widely used in physical anthropology, human biology, and studies of human evolution to compare populations and understand patterns of human variation. Although modern anthropology recognizes that cranial index alone cannot determine race or ancestry, it remains an important descriptive tool in osteology, forensic anthropology, archaeology, and evolutionary studies. The cranial index was introduced by the Swedish anatomist Anders Retzius in the nineteenth century. It provides a numerical value that expresses the relative proportions of the skull. The index is calculated by measuring the maximum width of the skull and comparing it with its maximum length. These measurements are taken using specialized anthropometric instruments such as spreading calipers. The formula for calculating the cranial index is: Cranial Index = (Maximum Cranial Breadth ÷ Maximum Cranial Length) × 100 The maximum cranial breadth refers to the greatest distance between the two parietal bones of the skull. The maximum cranial length is the distance from the glabella, located between the eyebrows, to the opisthocranion, the farthest point at