The present invention concerns current transducers for measuring a current flowing through a cable. The current transducers have a ferromagnetic core providing a substantially ring-shaped portion and at least two legs. The ring-shaped portion has one air gap or two air gaps. A magnetic field sensor is placed in or at each of the air gap(s). The ring-shaped portion forms a magnetic circuit that encloses the cable and guides the magnetic field generated by current to the air gap(s). Each leg extends from the center of the associated magnetic field sensor in a direction that runs perpendicularly to the longitudinal axis of the cable and has a certain length. The length of the legs is designed so long that at least two magnetic paths are formed which guide a component of an external magnetic field which extends in the direction of the legs around the magnetic field sensor(s).