Abstract: In a method for measuring a rotary tool use is made of a measuring device, which has an optoelectronic image acquisition device with optics alignable with the rotary tool and an image processing device for the computer-aided evaluation of acquired images. For measurement purposes a section of the rotary tool is brought into the image area of the optics and the rotary tool is rotated about its rotation axis. During rotation a sequence of frames of the rotating rotary tool is acquired. An evaluation of the frames is carried out with respect to at least one image parameter, which represents a measure for the positioning of the tool contour relative to the sharpness zone of the optics. By computer-aided selection a selection is made of the particular frame in which the image parameter corresponds to a positioning of the tool contour in the sharpness zone of the optics. This selected frame is used for determining at least one tool parameter characterizing the tool contour.