When and How to Use NPV, IRR and Modified IRR.
Net Present Value (NPV), Internal Rate of Return (IRR) and Modified Internal Rate of Return (MIRR). are summary measures of project performance. Each one provides a single figure summarizing the impact of the project on economic welfare. Each of the three measures does, however, give subtly different information. This Note considers when and how to use each measure in the economic evaluation of transport projects.
World Bank, Washington D.C., USA. Transport Note No. TRN-6, 9 pp.