Abstract: Disclosed is a groove measuring gauge. The gauge has a centering headpiece and centering tailpiece for supporting a die or other workpiece mounted upon an arbor. Two guideways are used to position a gauge head near the workpiece containing the groove being measured. The gauge head has a spindle rotatably mounted therein. The spindle includes a measuring arm which extends from an interior cavity in the spindle. The measuring arm is pivotably mounted in the spindle. The exposed end of the measuring arm contacts the inside surfaces of the groove. A micrometer is mounted upon the spindle and connected to the enclosed end of the measuring arm. As the measuring arm pivots the micrometer measures the distance from the spindle axis to the surface of the groove. The spindle is preferably automatically moved to angular positions by a stepping motor. Micrometer readings are taken at each position and the profile of the groove is determined from these measurements.