The objective of the work was to provide empirical evidence to readers of the formulation and evaluation of investment projects on the estimation, importance, interpretation and manual demonstration of traditional and complementary profitability indicators Net Present Value (NPV), Internal Rate of Return (IRR), Benefit/Cost Ratio (BCR), Desirability Index (DI) and demonstrate that the Modified Internal Return Rate (IRRM) is a better financial indicator than the IRR to assess the profitability of an investment project. A hypothetical exercise was proposed, and various simulations were performed with the Minimum Acceptable Profitability Rate (MAPR) to observe the behavior between it and the profitability indicators. It was found that the indicators, NPV, BCR, DI, IRR and IRRM increase the accuracy of the financial analysis, therefore, their use by analysts and academics both to evaluate an investment and to complement the information provided by the NPV increases efficiency in Decision making for any investment project analysis. It was shown that the IRRM is a better indicator of profitability than the IRR and that its result depends on the behavior of the MAPR, which presented an inverse relationship with the DI; however, this indicator can be used in conjunction with the IRRM to complement an appropriate investment decision.