A multi-sensor, real-time, in-process current and voltage estimation system is disclosed including sensors, affiliated hardware, and data processing algorithms that allow accurate estimation of currents and voltages from magnetic and electric field measurements, respectively. Aspects of the system may be embodied in a detector that is readily attachable to conductors of an energized system for contactless current and/or voltage sensing of the conductors without requiring the conductors to be disconnected from the energized system.