Why Excel falls short The Internal Rate of Return is a key metric used by investors, business managers and many other decision-makers to evaluate project profitability and viability. In the past, an ...

You can calculate an IRR in three ways: using the IRR function in Excel, using a financial calculator or by hand, guessing the discount rate at which the net present value will equal zero.

Capital lease interest can be computed using the IRR function in a spreadsheet. Adjust IRR formula for payment frequency to get correct annual interest rates.