Which is the longest bone in the human body?

The story behind the answer

The femur—your thigh bone—is the longest (and strongest) bone in the human body, running from the hip to the knee. It bears most of your body weight and transmits powerful forces during standing, walking, and jumping, which is why it’s thick and dense. In adults, it typically measures around 45–50 cm. By contrast, the ulna is a forearm bone, the fibula is the slimmer bone of the lower leg, and the scapula is a flat shoulder blade.

Memory tip: F for Femur, F for “Full-length” thigh. The femur anchors major muscles and forms both the hip and knee joints—key features of our bipedal locomotion.