A new method to estimate the sulfate aerosol hygroscopicity parameter (κSO₄) is suggested that can consider κSO₄ for two different sulfate species instead of prescribing a single κSO₄ value, as in most previous studies. The new method simulates more realistic cloud droplet concentrations and, thus, a more realistic cloud albedo effect than the original method. The new method is simple and readily applicable to modeling studies investigating sulfate aerosols’ effect in aerosol–cloud interactions.