An electronic weight scale includes: a main scale module including a main weight sensor disposed in a main housing and outputting an output corresponding to weight acting on the main housing and sensed thereby, a controller operable in one of folded and unfolded modes in response to a control signal from an input unit, and a display unit mounted on the main housing; and an auxiliary scale unit connected pivotally to the main scale module and including an auxiliary scale module that has an auxiliary weight sensor disposed in an auxiliary housing and outputting an output corresponding to weight acting on the auxiliary housing and sensed thereby. The controller outputs weight information, that indicates the output from the main weight sensor when in the folded mode and that indicates a sum of the outputs from the main and auxiliary weight sensors when in the unfolded mode, to the display unit.