Abstract: A device and method used in a spindle or fixture to measure tool sizes. The device has two conical 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 conical shapes which is visible exposed when mounted and used. The end of the device is at the end of the smaller of the two conical shapes which is hidden after mounting. The combination of using the device and method will allow more accurate programming of machine tools which in turn will provide higher quality results on machined work pieces and reduced machining cycles.