An adult human skeletal system is commonly said to contain 206 bones. This is the standard anatomical count used in general education, although individual totals can vary slightly.
The skeleton is divided into two major sections. The axial skeleton contains 80 bones, including the skull, vertebral column, ribs, sternum, and associated bones. The appendicular skeleton contains 126 bones, including the shoulder and pelvic girdles and the bones of the arms and legs. Together, these groups total 206.
Babies are born with roughly 270 bones. As the body grows, several bones fuse, especially in the skull, pelvis, sacrum, and coccyx. That is why the adult count is lower. Some people also have additional small accessory bones, such as extra sesamoid or sutural bones, so 206 is a conventional reference number rather than an unbreakable limit.
The number can also change depending on counting rules. For example, the fused bones of the sacrum may be counted as one bone in an adult, while their separate developmental parts may be considered individually.