Abstract: Objectives A practical computational method based on Neumann-Kelvin（NK）theory is proposed for rapid calculation of wave-making resistance. Method The boundary integral equation is discretized and solved using the Kelvin source Green’s function. The numerical computations of wave-making resistance, sinkage, trim and free surface elevation for the Wigley, S60, and KCS hull forms are conducted using a self-developed Fortran program to investigate the effects of waterline integration and different computational approaches. Results The results demonstrate that simplifying the waterline integral term allows for reasonably accurate solutions to ship wave problems. Longitudinal wave cuts exhibits low sensitivity to mesh density, therefore wave pattern analysis effectively balances computational efficiency and accuracy. Conclusions This study provides a simplified and rapid practical tool for ship resistance evaluation and optimization.