Deep drawing is one of the most widely adopted sheet metal forming processes for manufacturing lightweight, high-strength, and dimensionally accurate components used in the automotive, aerospace, household appliance, and packaging industries. Among the numerous parameters affecting the quality of deep-drawn products, the geometry of the initial blank plays a decisive role in controlling material flow, flange deformation, trimming allowance, thickness distribution, and the occurrence of common forming defects such as wrinkling, tearing, and excessive earing. Although extensive research has been devoted to the optimization of circular blank geometries, the design of optimal blanks for rectangular deep-drawn components remains considerably more challenging because of the non-axisymmetric material flow and the highly non-uniform strain distribution developed along the flange and corner regions. This study presents a computational methodology for the optimal design of the initial blank geometry for rectangular deep-drawn parts with the objective of minimizing trimming waste while maintaining satisfactory forming quality. An analytical material-flow formulation based on curvilinear coordinates is implemented within a SolidWorks environment through a customized Visual Basic application that automatically generates the optimum blank contour directly from the three-dimensional geometry of the desired component. The developed algorithm calculates the initial blank profile, reconstructs its geometry in Cartesian coordinates, and compares the optimized blank with several conventional blank configurations, including rectangular, elliptical, octagonal, and diamond-shaped blanks. The generated geometries are subsequently validated using nonlinear finite element simulations performed in ABAQUS to investigate material flow characteristics, deformation behavior, and the final trimming profile.Simulation results demonstrate that the proposed methodology significantly reduces trimming waste while improving material utilization compared with conventional blank geometries. Furthermore, the optimized blank exhibits a more uniform material flow toward the die cavity, resulting in a more homogeneous strain distribution and a noticeable reduction in localized deformation. The comparison between different blank geometries confirms that although octagonal blanks outperform other conventional alternatives, the proposed optimized contour consistently provides the minimum trimming allowance and the highest material efficiency. The developed computational framework offers a practical and computationally efficient tool that can readily be integrated into industrial computer-aided design environments for rapid blank design in deep drawing applications involving rectangular geometries.