An ion trap mobility spectrometer calibration system and method wherein the maximum response of the spectrometer is determined. A quantity Q.sub.0 is chosen representing a response which is a predetermined percentage of the maximum response. Input to the ion trap mobility spectrometer are at least two known quantities Q.sub.1 and Q.sub.2 of an analyte, which have a predetermined relationship with Q.sub.0. The responses corresponding to R.sub.1 and R.sub.2 of the ion trap mobility spectrometer are observed based on the respective inputs of quantities Q.sub.1 and Q.sub.2. R.sub.1, R.sub.2, and Q.sub.1 and Q.sub.2 are then used to calculate the calibration constants in an equation describing a curve where the response of the ion trap mobility spectrometer is a function of the quantity of the analyte input therein. The calculated calibration constants are input to thereafter determine, from the response, the quantity of a detected analyte based on the equation.