A method is presented for calculating the densities of simple and multicomponent aqueous saline solutions. A total of 38 parameters were obtained for anions and cations which allowed predicting their density in aqueous solution. The proposed method is based on the model of Hórsak and Slama¹ applicable to simple 1:1 aqueous electrolyte solutions which in the present study was extended to multicomponent systems and for any type of salt. Seventeen aqueous systems containing 2, 3, and 4 salts were studied, obtaining excellent results when compared with the experimental values. The total relative mean standard deviation obtained was 0.08 %. The proposed method used adjustable parameters, which are obtained beginning from experimental data from systems containing a single salt. Two parameters are required for each ion present in the aqueous solution