A method of calibrating a pipelined analog to digital converter having a plurality of DAC elements and an additional calibration DAC element is provided. In the method as provided herein, a combination of positive, negative and zero reference voltages are applied to the element under calibration and positive and negative reference voltages are applied to the additional calibration DAC element to obtain four calibration states. An error of the DAC element under calibration is extracted by calculating an average of the difference between the four calibration states.