In this article, structural characteristics of amorphous and crystalline domains of various cellulose triesters were studied. These triesters contained three acyl substituents having a different number of carbon atoms. To calculate the structural characteristics of amorphous esters, the Van Krevelen method of additive contributions of partial volumes of atoms and atom groups in the molar volume of amorphous polymers was used. A special correction for the molar volume of amorphous esters was made to calculate the molar volume of crystallites of cellulose esters. Based on the molar volume, also specific volume and specific gravity of amorphous and crystalline domains of cellulose triesters were found. The coincidence of calculated and experimental characteristics was shown. In addition, the correlation equations were derived, which provide predicting the structural characteristics of various cellulose esters in the amorphous and crystalline phase states.