We present in this article a new method to determine the "geometrical" surface area of nonporous solids. This method is based on the total number of molecules dosed into the adsorption cell and a knowledge of the distribution of molecules between the gas phase and the suffice phase. By matching this experimental amount with the corresponding theoretical equation. we can derive not only the surface area hut also its energy distribution and the void volume of the adsorption cell, The method avoids the limitations of other methods presented in the literature. The BET method. for example. involves unrealistic assumptions and necessitates the choice of a molecular projection area. Our method does not suffer from these assumptions or limitations and is self-consistent. from the measurement of adsorption data to the final analysis of the surface area. The novelties of the method are the following: (i) it is valid over the complete range or reduced pressure, (ii) it does not require a molecular projection area, (iii) beside the total surface area, we also derive its energy distribution, and (iv) the helium expansion method (or any equivalent method) is not required to determine the void volume.