A method of using a power consumption measurement device , the method comprising: determining one or more first magnetic field readings from one or more main electrical supply conductors for an electrical power infrastructure of a structure using one or more sensors in the power consumption measurement device ; after determining the one or more first magnetic field readings, electrically coupling a first calibration load to the electrical power infrastructure; while the first calibration load remains electrically coupled to the electrical power infrastructure, determining one or more second magnetic field readings from the one or more main electrical supply conductors using the one or more sensors in the power consumption measurement device ; calibrating the power consumption measurement device using at least in part the one or more first magnetic field readings and the one or more second magnetic field readings, wherein calibrating the power consumption measurement device comprises: determining one or more first calibration coefficients for the power consumption measurement device using at least in part the one or more first magnetic field readings and the one or more second magnetic field readings; after calibrating the power consumption measurement device , determining one or more third magnetic field readings from the one or more main electrical supply conductors using the one or more sensors in the power consumption measurement device ; and determining an electrical power used by the electrical power infrastructure of the structure using at least the one or more third magnetic field readings and the one or more first calibration coefficients, wherein the power consumption measurement device is coupled to an exterior surface of a circuit breaker box that overlies at least part of one or more main electrical supply conductors without exposing the power consumption measurement device to contact with the one or more main electrical supply conductors. determining one or more first magnetic field readings from one or more main electrical supply conductors for an electrical power infrastructure of a structure using one or more sensors in the power consumption measurement device ; after determining the one or more first magnetic field readings, electrically coupling a first calibration load to the electrical power infrastructure; while the first calibration load remains electrically coupled to the electrical power infrastructure, determining one or more second magnetic field readings from the one or more main electrical supply conductors using the one or more sensors in the power consumption measurement device ; calibrating the power consumption measurement device using at least in part the one or more first magnetic field readings and the one or more second magnetic field readings, wherein calibrating the power consumption measurement device comprises: determining one or more first calibration coefficients for the power consumption measurement device using at least in part the one or more first magnetic field readings and the one or more second magnetic field readings; after calibrating the power consumption measurement device , determining one or more third magnetic field readings from the one or more main electrical supply conductors using the one or more sensors in the power consumption measurement device ; and determining an electrical power used by the electrical power infrastructure of the structure using at least the one or more third magnetic field readings and the one or more first calibration coefficients, <EOS>