The significant correlation of skull fracture with fatal head injury suggests such fracture prevention to be a useful minimal design criterion. A spherical cap under dynamic local loading is recommended as an effective mathematical model to assess skull fracture. With finite difference techniques in space and time, the governing large deformation cap equations are solved for a circular load area. For load pulses of practical significance, the only parameters of concern are load area, load amplitude, skull thickness and maximum allowable stress. Curves are presented of fracture load with load area for various skull thicknesses. Results suggest that increasing the load area greatly diminishes the possibility of fracture. Hence, helmet and vehicle designers should aim towards this end.