Abstract: An improved caliper apparatus comprises a host caliper including a jaw assembly having two opposing, flat reference edges for measuring edge-to-edge and point-to-point distances; and further includes removable, reference off-setting assemblies which are removably attached to the jaw elements of the host caliper; and which reference off-setting assemblies reposition the reference points of the caliper to provide hole-to-hole and edge-to-hole measurements while maintaining the integrity of the direct reading off the caliper scale.