Currently, uoroscopy and conventional digital subtraction angiography are used for imaging guidance in endovascular aortic repair (EVAR) procedures. Drawbacks of these image modalities are X-ray exposure, the usage of contrast agents and the lack of depth information. To overcome these disadvantages, a catheter prototype containing a multicore fiber with fiber Bragg gratings for shape sensing and three electromagnetic (EM) sensors for locating the shape was built in this study. Furthermore, a model for processing the input data from the tracking systems to obtain the located 3D shape of the first 38 cm of the catheter was introduced: A spatial calibration between the optical fiber and each EM sensor was made in a calibration step and used to obtain the located shape of the catheter in subsequent experiments. The evaluation of our shape localization method with the catheter prototype in different shapes resulted in average errors from 0.99 to 2.29 mm and maximum errors from 1.73 to 2.99 mm. The experiments showed that an accurate shape localization with a multicore fiber and three EM sensors is possible, and that this catheter guidance is promising for EVAR procedures. Future work will be focused on the development of catheter guidance based on shape sensing with a multicore fiber, and the orientation and position of less than three EM sensors.