Abstract: A unitary guide tool that provides a guide for measuring and marking a work piece when moved along an edge thereof, the guide tool being in the form of a generally rectangular offset or stepped bar of material having a thicker section forming a stepped side for engaging the edge of a work piece in a first disposition and engaging a measuring tape dispensing housing in another disposition, the block being slidable along an edge of the work piece and having a longer dimension extending generally perpendicular thereto.