A capacitance measuring system, including: a calibration capacitor; first circuitry for sensing an input current at an input thereof and generating an output signal that is based upon a capacitance appearing at the input of the first circuitry; and multiplexer circuitry, coupled between the input of the first circuitry and a terminal of each of the capacitor to be measured and the calibration capacitor, for selectively coupling the terminal of each, one at a time, to the input of the first circuitry while the terminal not coupled to the input of the conversion circuitry is coupled to a ground reference; and controller circuitry for calculating a capacitance of the capacitor to be measured based upon the output signal of the first circuitry when the capacitor to be measured is coupled to the input thereof and upon the output signal of the first circuitry when the calibration capacitor is coupled to the input thereof.