Provided is a multiplier-accumulator (MAC) system, circuit, and method. The MAC system includes a MAC circuit, including a plurality of resistors, having respective resistances, a capacitor connected to the plurality of resistors to charge, in response to a plurality of input signals, the capacitor with electric charge, and a time-to-digital converter (TDC) configured to convert information of a charge time of the capacitor, due to the electric charge, into a digital value, wherein the digital value is an accumulation result of the MAC circuit.