A positioning jig for locating drill holes or other targets in a workpiece on which the positioning jig is positioned. The positioning jig includes a pinion body and a pair of arms extending from the pinion body. The pair of arms are engaged with a pinion in the pinion body to provide a rack and pinion mechanism for centering the positioning jig on a workpiece. A jig body including at least one aperture is connected with the pinion body. The jig body may be translated with respect to the pinion body for locating the at least one aperture at a target point on the workpiece for drilling a hole or marking the workpiece.