You can use IRR and NPV to calculate internal rate of return and net present values for even interval cash flows. In the examples, you saw in the previous chapters, we used even end-of-year cash flows. The functions can handle similar end-of-month cash flows.
For uneven interval cash flows, use the XNPV and XIRR functions. They are part of the Excel Analysis ToolPak Add-In. If you use the Add-In, you may remember how to activate it. To invoke the Add-In, click on the Office button ⇒ Excel Tools ⇒ Add-Ins and activate the Analysis ToolPak. Excel 2011 for the MAC has these functions available without the ToolPak.
Let me repeat the process here if you did not read Chapter 13, and explain how to activate the Analysis ToolPak Add-In. Follow these steps:
It will take Excel a few seconds to install the Analysis ToolPak. For the Mac you do not have to activate the Analysis ToolPak. The XNPV and XIRR functions ...