This study aims at linking micro-structure key parameters with the measured macroscopic properties of nano-clay reinforced Poly(lactic acid) (PLA) and Poly(carbonate) (PC) through multi-scale sensitive mechanical model. Nano-clay platelets domain size and distribution were investigated using TEM observation. In case of intercalation, d-spacing between nano-platelets were measured using X-ray diffraction. Platelets domain size along with distance between platelets within the platelets stack were used as inputs for micro-mechanical models. To predict the macroscopic elastic properties, three approaches were considered; hybrid, matrix-inclusion models and their combinations. This last approach allows to take into account intercalated micro-structure by replacing the platelets properties by a stack of bi-layered sandwiches made of nano-clay platelets and polymer layers. Experimentally measured Young’s modulus were well bounded by the model predictions.