Aspects of the present disclosure relate to approaches for determining position and orientation of a tracked tool in a medical navigational context. In one embodiment, the position of a surgical or interventional tool may be determined using the orientation or field direction data such that the determination is independent of field strength or magnitude. Feedback may be provided to a user based on these determinations. In certain embodiments, the navigational system may be auto-calibrated using position information determined independent of field strength or magnitude.