Computational methods used for estimation the effects of dynamic loading on buildings need to be developed and updated to ensure structural safety. A computer program, YAY2020-Dynamic was developed using the Matlab interpreter to calculate the effect of dynamic forces on planar structures. The program successfully estimated the impact of dynamic forces on structures. The main feature of the program is that it uses mass and stiffness matrices with both diagonal and non-diagonal elements. Furthermore, the developed program uses 12 × 12 matrices in shear formulations to include moment and rotation effects perpendicular to the plane. These features were not used in the literature and have not been studied on high-rise buildings before. Modal analysis (Eigen analysis) and time history analysis (Newmark analysis) are performed in the program for dynamic analysis of high-rise buildings. A special formulation is used to include angular and rotation freedom parameters in the mass and stiffness matrices of plate elements. These matrices were presented for the first time in this study as 12 × 12 matrices with diagonal and non-diagonal elements. The core principle of the program is to make more realistic modeling by considering as many mechanisms as possible, instead of making assumptions and neglecting some parameters that limit representing real behavior. To determine the performance of the developed program, two buildings (a 10-story and a 20-story) were examined. According to the results, YAY2020-Dynamic determined that the examined building models were more rigid and had fewer deformations than the estimated by SAP2000. Therefore, the use of YAY2020-Dynamic in design stages can help determine the required member strengths more precisely and choose the proper building materials while considering the safety factors.