A method for manufacturing an ultrahard compact includes assembling a mass of ultrahard material with a mass of substrate material such that the mass of ultrahard material extends radially outward a greater extent than the substrate material to compensate for a difference in the radial shrinkage of the ultrahard material compared to the substrate material during a sintering process. The method may further includes subjecting the assembled compact to a high pressure high temperature process that results in the forming of an ultrahard compact including an ultrahard layer integrally bonded with a substrate.