In this work, a model capable of adequately correlating and reproducing experimental adsorption isotherm data in the overall relative pressure range is Suggested. The equation includes a Dubinin-Radushkevich term and a modified BET term that avoids the discontinuity of BET equation at high relative pressures. Thus, the typical independent application of the Dubinin-Radushkevich and BET equations, involving the need of a selection of the respective relative pressure range, is substituted by a single optimization procedure, permitting the calculation of the values of the parameters characterizing the textural properties of solids. The validity of the procedure has been checked through its application to several experimental examples, corresponding to types I, II, and IV isotherms, showing excellent results in all of the cases.