Method for determining an individual power consumption in an electric installation comprising a group of individual electricity distribution branches and an upstream main line connecting the group of branches to an electric power supply, each individual electricity distribution branch comprising a circuit breaker, method comprising the following steps: a) measuring the current flowing in the upstream main line and the voltage of the upstream main line; b) measuring the voltage (U i) of at least one individual distribution branch, downstream from the circuit breaker; c) determining the current (I i) flowing in the individual distribution branch from the difference (ΔU i) between the voltage of the upstream main line and the voltage of the individual distribution branch; d) calculating the individual power consumption (P i ') of the individual distribution branch from the current (I i) and the voltage (U i) of the individual distribution branch; e) calculating the global power consumed by the group of branches from the current and the voltage of the upstream main line; and f) correcting the individual power consumption (P i '), so that an instantaneous variation of electric consumption observed on the individual distribution branch is equal to an instantaneous variation of electric consumption observed simultaneously on the upstream main line, method wherein step f) comprises the following sub-steps: - assigning an individual correction coefficient (α i) to the individual power consumption (P i '); - simultaneously detecting a variation (ΔP i) of the corrected individual power consumption and a variation (ΔP) of the global power; - calculating a calibration coefficient (R i) equal to the ratio between the variations (ΔP i, ΔP) of individual power consumption and of global power; - updating the individual correction coefficient (α i) by means of the calibration coefficient; and - assigning the individual correction coefficient (α i) to the individual power consumption (P i '). a) measuring the current flowing in the upstream main line and the voltage of the upstream main line; b) measuring the voltage (U i) of at least one individual distribution branch, downstream from the circuit breaker; c) determining the current (I i) flowing in the individual distribution branch from the difference (ΔU i) between the voltage of the upstream main line and the voltage of the individual distribution branch; d) calculating the individual power consumption (P i ') of the individual distribution branch from the current (I i) and the voltage (U i) of the individual distribution branch; e) calculating the global power consumed by the group of branches from the current and the voltage of the upstream main line; and f) correcting the individual power consumption (P i '), so that an instantaneous variation of electric consumption observed on the individual distribution branch is equal to an instantaneous variation of electric consumption observed simultaneously on the upstream main line, - assigning an individual correction coefficient (α i) to the individual power consumption (P i '); - simultaneously detecting a variation (ΔP i) of the corrected individual power consumption and a variation (ΔP) of the global power; - calculating a calibration coefficient (R i) equal to the ratio between the variations (ΔP i, ΔP) of individual power consumption and of global power; - updating the individual correction coefficient (α i) by means of the calibration coefficient; and - assigning the individual correction coefficient (α i) to the individual power consumption (P i ').