The invention relates to a method and device for contactless or touch-free measurement of a tool by imaging. A processor makes calculations based on image points on the tool, imaged onto an imaging area. Optics present the image of the image points on the tool on the imaging area. The processor calculates the momentary position and/or orientation along at least one axis of the tool making use of the image points. A number of measuring markers have predetermined mutual positions and are on the tool. Each measuring marker comprises at least one measuring point. At least one of the points is identifiable. Each measuring marker to be used as position and/or orientation indicator has a size making it restorable by the processor even if a part of it on the tool is obscured from the image area, for example by dust.