It is widely known that decorating metal atoms on defective carbon nanomaterials is a useful approach to enhance the hydrogen storage capacity of these systems. Herein, density functional theory calculations are used to determine the H2 storage capacity of Ca functionalized nitrogen incorporated defective C60 fullerenes (Ca6C24N24). The strong binding, uniform distribution, and significant positive charges of the Ca atoms make this system effective material for storage of H2. Ca6C24N24 may adsorb a maximum of 6 hydrogen molecules per Ca atom, yielding a total gravimetric density of 7.7 wt %.