# Stiffness to Weight Ratio (Specific Stiffness)

The stiffness-to-weigth ratio is a measure of a material's mass efficiency in being able to provide resistance to elastic deformation. In the *axial* mode, it is calculated as tensile modulus divided by density. In the *bending* mode, it is calculated as the cube root of tensile modulus divided by density. This corresponds to a scenario where section height is the free variable for an otherwise specified beam. In both cases, the derived units have little physical significance, and "points" are used instead.