The present invention relates to a method and a system for determining the relation between a local coordinate system located in the working range of an industrial robot (1) and a robot coordinate system. The method comprises: attaching a first calibration object (10) in a fixed relation to the robot, determining the position of the first calibration object in relation to the robot, locating at least three second calibration objects (14, 15, 16) in the working range of the robot, wherein at least one of the calibration objects is a male calibration object having a protruding part shaped as a sphere, and at least one of the calibration objects is a female calibration object comprising at least two nonparallel, inclining surfaces arranged to receive the sphere so that the sphere is in contact with the surfaces in at least one reference position, determining a reference position for each of the second calibration objects in the local coordinate system, for each second calibration object moving the robot until the sphere is in mechanical contact with the surfaces of the calibration object, reading the position of the robot when the sphere is in mechanical contact with all of the surfaces, and calculating the relation between the local coordinate system and the robot coordinate system based on the position of the first calibration object in relation to the robot, the reference positions of the second calibration objects in the local coordinate system, and the positions of the robot when the sphere is in mechanical contact with the surfaces of the second calibration objects.