Remote magnetic navigation offers various possibilities for medical interventions. Magnetic catheters can be wirelessly steered with high precision and accuracy through complex structures, as they are generally more dexterous and flexible than their manually steered counterparts. Position feedback is essential for many tasks. However, most commercially available systems do not integrate well with the magnetic navigation systems. As a result, fluoroscopy is still widely used in many interventions despite the known associated health risks. In this study, we propose a localization method that uses multiple Hall sensors to measure the magnetic fields produced by the magnetic navigation system and estimate the full sensor pose without the need for a separate dedicated mapping system. This makes the magnetic navigation system a 2-in-1 system that can be used for simultaneous navigation and localization of a medical tool. We perform an optimization of the sensors’ array design in simulation and investigate the influence of the magnetic fields and gradients on the localization accuracy to provide information on the minimal requirements for a magnetic navigation system for this task.