Disclosed is a battery management apparatus and method for calibrating the state of charge (SOC) of a lithium iron phosphate (LFP) battery. The battery management apparatus according to an embodiment of the present disclosure calculates, when going into calibration mode, an average voltage value of voltage values received from a voltage measuring unit for a predefined time, calculates an average current value of current values received from a current measuring unit for the predefined time, calculates an average internal resistance value of the LFP battery for the predefined time based on the average voltage value and the average current value, determines if the average internal resistance value is equal to or larger than a preset reference resistance value, and when the average internal resistance value is equal to or larger than the reference resistance value, calibrates the current SOC to a preset reference SOC.