A device used in a spindle or fixture to measure tool sizes. The device has two cylindrical shapes that have precision machined surfaces. The device's face has a precise size which is the same nominal size as that of a material removing tool. The device's shaft allows for concentric and precision fastening of the device to a spindle or a fixture. The nose of the device is located on the end of the larger of the two cylindrical shapes which is visible exposed when mounted and used. The end of the device is at the end of the smaller of the two cylindrical shapes which is hidden after mounting. The device allows more accurate programming of machine tools thus providing higher quality results on machined work pieces and reducing machining cycles.