A bidirectional logic gate has been designed based on the backhopping phenomenon observed in magnetic tunnel junctions (MTJ) at high bias. The magnetization dynamics of each magnetic layer of the MTJ—having materials and geometry of a standard spin-transfer torque magnetic random access memory device—is calculated using the coupled Landau–Lifshitz–Gilbert equation-based theoretical framework. A circuit design interconnecting the MTJs has been proposed to simulate a two-input NAND gate. The results in both forward and reverse directions agree well with those found from the Boltzmann distribution, thereby demonstrating the equiprobability of all valid states.