A simple mathematical model for predicting the crushing stress of composite materials was derived and presented in this article. The present knowledge of fracture mechanics and strength of materials are used as the basis for the model. The fracture mechanics part of the analysis was based on energy release rate approach; the energy release rate, G, of the proposed model was determined by this approach. This energy release rate was based on the Mode I (opening or tensile mode) failure. As for the strength of materials part analysis, buckling theory was used to determine the critical load of the fiber beams. These two engineering concepts were combined to form the equation for the proposed model. The derived equation is a function of the materials properties, geometric, and physical parameters of the composite materials. The calculated stresses from the derived equation were compared with experimental data from technical and research articles. Good agreements shown in the results are encouraging and recommendations for future analysis with different modes of failure were also presented. This article enables engineering designers to predict crushing stress in composite materials with confidence and makes their work more efficient and reliable.