In order to conveniently calculate the group delay ripple of the bulk acoustic wave (BAW) filter by the S parameters measured by the vector network analyzer, two methods of calculating the group delay ripple of BAW filter in ADS and MATLAB are put forward. In this paper, the calculation and the calculating process of group delay ripple by the MATLAB programming and ADS are introduced, and the two methods are compared. Then, the difference between using “delay (S12)” and “group_delay” to calculate the group delay ripple in ADS is pointed out. The results show that the calculation in MATLAB is basically consistent with the group delay ripple calculated in ADS using “group_delay” and both can accurately calculate the group delay ripple of the BAW filter.