We apply the calculable R-matrix method to determine the cross sections of the \(^{12,13}\) C( \(p,\gamma \) ) \(^{13,14}\) N reactions using both local Woods-Saxon (WS) and nonlocal Perey-Buck (PB) potentials. Benchmark calculations are first performed for the \(^{12}\) C( \(p,\gamma \) ) \(^{13}\) N reaction, and the results show good agreement with the standard codes FRESCO and RADCAP, as well as with recent calculations in other works. Furthermore, the method is applied to investigate the \(^{13}\) C( \(p,\gamma \) ) \(^{14}\) N reaction. Analysis of the astrophysical S-factors for both reactions indicates no significant difference between the local and nonlocal potential calculations, with discrepancies limited to approximately 7%–8%. The successful application of the calculable R-matrix method to these \((p,\gamma )\) processes provides a framework for future studies involving nonlocal potentials derived from microscopic models.