Soft micropillar arrays enable detailed studies of cellular mechanotransduction and biomechanics using traditional beam-bending models. However, they often rely on simplified assumptions, leading to significant errors in force estimation. We present MechanoBioCAD (MBC), a finite element method (FEM)-based tool designed specifically for micropillar research and error estimation. Unlike traditional methods, MBC leverages the principle of minimizing total potential energy, avoiding errors associated with beam bending assumptions. MBC automates FEM model generation, analysis, and post-processing, providing accurate force quantification based on deflection input. The tool addresses critical issues such as substrate deformation, interpillar interactions, improper load application heights, and nonlinear effects. Applied to fibroblast cell traction and