The essence of the blast load relies on the factors such as explosive weight, standoff distance of the structure from the explosive, the location of the explosion concerning the structure, shape of the protective structure, and orientation of the structure relative to the explosion. The study provides an approach for calculating blast wave parameters according to IS 4991-1968 and UFC 3-340-02 and demonstrated by examples. It concludes that, in Indian Standard, only positive blast wave is considered but in UFC, both the positive as well as negative blast wave is taken into consideration. Also, there are significant differences in evaluating the parameters as per both standards.