A new generalized model was developed for the density calculation of single and mixed electrolyte solutions in the temperature range of 273.15–373.15 K by using the principle of corresponding states and the main idea of the TTG model for electrolyte aqueous solutions. The molar volume of electrolyte solutions consists of both intrinsic ionic volume and apparent water molar volume; the former was evaluated from the expression given by Conway (1981, Studies in physical and theoretical chemistry 12. Amsterdam: Elsevier) expression and the latter from the generalized relationship between apparent water molar volume and osmotic pressure. The validity of the proposed model was extensively tested for 151 single and 30 binary electrolyte solutions at 298.15 K, and 11 single electrolyte solutions in the temperature range of 273.15–373.15 K. With the optimized ionic radii which is temperature and concentration independent, the AADs were found to be within 1% for single and binary-electrolyte solutions.