Bone mineral content as determined by computed tomography (CT) and mechanical strength on axial loading were compared in 36 cadaveric femur specimens. In axial loading, 34 femora fractured vertically in the neck, one femur fractured subtrochanterically, and one in the shaft. Based on the CT measurements of density and area, the mass of a transverse slice of the femur was estimated. Highly significant correlations were demonstrated between strength and cancellous bone density. Even higher correlations were revealed when the bone masses of the proximal and distal femoral areas were calculated. Based on these findings, an equal distribution of the effective mass of the femur was postulated.