Embodiments of the present disclosure include a method for determining a shape of a catheter. The method can include receiving a plurality of impedance measurements from a plurality of electrodes disposed on a flexible tip portion of the catheter. The method can include receiving a magnetic position measurement from a magnetic position sensor disposed on a shaft of the catheter. The method can include determining a relationship between each of the plurality of electrodes disposed on the flexible tip portion of the catheter, based on the impedance measurements received from the plurality of electrodes. The method can include predicting a shape of the flexible tip portion of the catheter, based on the determined relationship between each of the plurality of electrodes disposed on the flexible tip portion of the catheter. The method can include determining a shape of the catheter, based on the magnetic position measurement and the predicted shape of the flexible tip portion.