Excess molar volumes, $$ V_{123}^{\text{E}} $$ V 123 E , of 1, 3-dioxolane (1) + toluene (2) + o- or p-xylene (3) ternary mixtures have been determined dilatometrically over the entire composition range at 298.15 K. For thermodynamic consistency the experimental values were fitted to Redlich–Kister Equation. The $$ V_{123}^{\text{E}} $$ V 123 E values of 1, 3-dioxolane (1) + toluene (2) + o- or p-xylene (3) ternary mixtures have been found to be negative over the whole composition range. It has been observed that $$ V_{123}^{\text{E}} $$ V 123 E values calculated by graph theory are of the same sign and magnitude with respect to their experimental values.