This method is for determining the packed apparent bulk density of extruded catalysts. The method is applicable to catalysts conforming to the following approximate dimensions: a maximum diameter of 3.2 mm (1/8 inch) and a maximum average length of 9.5 mm (3/8 inch), with a maximum individual length of 15.9 mm (5/8 inch). Apparent bulk density, referred to as ABD, is an empirical value defined as weight per unit volume. The packed ABD of molecular sieves can be determined using UOP Method 563, “,Packed Apparent Bulk Density of Molecular Sieves,”, which addresses the hydrophilic nature of the material.