This page is intended as a facilitator for calculating decomposition kinetics. There are different approaches to using the most common equations. Herein we give three: the first-order kinetics function proposed by Jenny et al. (1949) and elaborated by Olson (1963); the double exponential suggested by Lousier and Parlinson (1976) and Bunell et al. (1977); and an asymptotic function suggested by Howard and Howard (1978). The functions are discussed more closely by Berg and Laskowski (2005; 2006) and by Berg and McClaugherty (2003).