Effective Continuum Micromechanics Analysis Code (EC-MAC) was developed to predict effective properties of composites containing multiple distinct nanoheterogeneities (fibers, spheres, platelets, voids, etc.) each with an arbitrary number of coating layers based upon either the modified MoriTanaka method or the self-consistent method. The influence of solid and hollow nanoreinforcement geometries and distinct elastic properties was addressed for solid silica nanosphere/epoxy, hollow glass nanosphere/polyester, and -zirconium phosphate nanoplatelet/epoxy composites, along with the influence of spherical voids. The notion of effective volume fraction was introduced to denote the fraction of nanoreinforcements that contribute to overall composite properties through their good dispersion. The predicted nanocomposite effective elastic moduli obtained using the Effective Continuum Micromechanics Analysis Code matched well with experimental results from the literature.