Abstract: A method and device for measuring the dimensions of a three-dimensional object (8) wherein the object is placed in a measuring corner which defines an x, y, z three-dimensional coordinate system, and wherein in connection with each coordinate at least one graded scale means (9) is provided. Optically machine-legible codes are provided along the respective graded scale means or a combined code for two axes together is provided in at least one of the coordinate planes. The projection of the objects on each coordinate (x,y,z) is registered by means of an opto/electrical reader ( 1,2) and the signals from the reader are fed into a computer (4) which, on the basis of the received signals for each coordinate, calculates and prints out, or displays, the characteristic data of the object. It can be used, for example, for freight charge calculations relating an object.