A simple way to verify the correctness of the calculation of GNI/IRR for an investment project

An easy way to verify the correctness of calculation of GNI (internal rate of return - IRR) in the economic assessment of an investment the project.

Substitute the resulting GNI value into your financial model as the initial value of the discount rate for the project (at which the discount coefficient is calculated for all periods of the calculation horizon) and recalculate the effectiveness of the project. Net discounted income (NPV) under this condition (and maintaining all other parameters) should be 0 or tends to be.

For example, we calculated the effectiveness of the project at a discount rate of 10%, received at the output HH 17% and BDD 120 thousand $. Now, instead of the 10% rate, we set 17% and recalculate the project again. Under this condition, the BDD should already be zero. This means that the GNI rate of 17% is calculated correctly and correctly for the project.