This chapter focuses on the practical programming of dual problems within DEA, providing essential tools for deeper economic interpretation. It begins by establishing the fundamental principles of duality in LP, which form the theoretical bedrock for DEA’s dual models. The tutorial then provides specific guidance on formulating and programming the dual counterpart of the SBM model. A key practical application is detailed: how to program the calculation of shadow prices for inputs and outputs directly from the dual SBM model’s solution, revealing their marginal values. The chapter extends this analysis to the more complex NDDF model, presenting the structure of its dual problem. Subsequently, it delivers instructions on programming the derivation of shadow prices based on the dual NDDF model, equipping researchers with the ability to perform nuanced economic analysis and resource valuation for a variety of advanced DEA applications.