Researchers developed a cost-effective method for determining the optimum mix design of graphite nanoplatelet (GNP) reinforced asphalt binders and mixtures. The optimal mix design is achieved by predicting the fracture behavior of these materials using simple laboratory testing and computer modeling. The model showed that using GNP in asphalt binders can significantly improve the strength and fracture energy of these mixtures compared to mixtures with unmodified asphalt binders. The model can be used as a design tool to determine what percentage of GNP is needed to achieve the necessary tensile strength for a target value of fracture energy.