A control system coupled to a pressure sensor calibrates the pressure sensor. The control system may measure a plurality of capacitance values at a plurality of corresponding applied voltages to compare the values with a first calibration mechanism generated by sample pressure sensors in a comparison. A final calibration mechanism may be generated by adjusting the first calibration mechanism in response to the comparison. The unknown differential pressure may be applied to a diaphragm of the pressure sensor. A capacitance value at the unknown differential pressure may then be measured. Using the final calibration mechanism, the differential pressure at the measured capacitance value may be retrieved.