A calibration device for use in an optical, part measuring system is provided. The device has a central axis and a plurality of regions which are rotationally symmetric about the axis. The device includes a series of step-shaped portions defining a multi-step region having a plurality of step edges. A profile of the multi-step region contains information for calibrating the system. The device further includes a plurality of cylindrically-shaped portions spaced apart along the axis and defining constant diameter regions containing information for calibrating the system. The device still further includes a frustum-shaped portion defining a pair of spaced, slope edge regions and a sloped region having boundaries marked by the pair of slope edge regions. The frustum-shaped portion has first and second diameters at its boundaries which define a range of diameters of parts capable of being measured in the system. A profile of the slope edge regions and the sloped region contains information for calibrating the system.