Determination of the catalyst mass is a challenging problem in the conceptual design of reactive distillation systems. In this work, we use the concept of countercurrent cascaded vapor-liquid reactors (CCRs) to develop a shortcut method for the design of binary reactive distillation columns. An analytical expression for the theoretical minimum catalyst loading can be derived as the number of CCRs approaches infinity. On the basis of this theoretical catalyst loading, we present a calculation procedure to obtain the catalyst mass and other basic process parameters, for example, number of reactive stages and number of separation stages, without a detailed model. Three real binary systems are used to illustrate this shortcut method, and the results show that the estimated shortcut designs are similar to the optimal designs.