Different mixing rules (Looyenga, Bottcher–Bordewijk, Mehrotra, Peon-Iglesias and Ideal relative permittivity of the mixture) were improved by considering the modification of volume fraction due to aggregation of solvent and solute molecules in the mixture for the calculation of effective permittivity of mixtures. The improved mixing rules were compared with experimental data andfitting residual was found lower than the original mixing rules. Among the improved mixing rules, the modified Looyenga mixing rulefits better than the others with an overall average absolute deviation percent (AAD%) of 1.10%.