Flexibility in designing custom pulse sequences has a direct impact on the development of diverse MR techniques and strategies. However, it is important to be cognizant of the MR safety risks that are associated with such custom sequences. We develop and evaluate an open source software package to predict global Specific Absorption Rate for Pulseq and TOPPE based sequences. We compare the resulting predictions with scanner reported SAR values for different flip angles and three sample weights, on two major MR vendor platforms. The predictions correlate highly with the scanner reported values: R2 = 0.87 (vendor 1); 0.99 (vendor 2).