This paper presents the comparison of three available models to estimate the effective interfacial area in a packed-bed liquid desiccant-air contact system. A case study is made for the application of a calcium chloride solution as the liquid desiccant. It is proposed that, for the preliminary design of a packed-bed liquid desiccant contactor, the Shi and Mersmann model can be used as the conservative model to estimate the effective interfacial area and the Onda et al. model is not suitable for the desiccant-air contact system. The Shulman et al. model reveals that the effective interfacial area has lesser influence from air mass flux and air density and, hence, they can be neglected. Further, the effective interfacial area that is estimated for the desiccant-air contact system is about 17% lower than that of the water-air contact system. The effects of the size and shape of the random packing materials on the effective interfacial area are studied and briefly discussed in the paper.