Select "Insert" and click on "Function..." This will bring up a list of functions you can use. IRR, XIRR, and MIRR are all listed here.
I'm looking for a spreadsheet, already completed, where I can input a series of annual costs, and a series of derived savings in other cells for a lets say a 10 year period.
In an excel spreadsheet...
1) Input your total costs for the project in one column (lets say column "A".
2) Input your income (derived savings etc...) for the project (lets say column "B"
3) Set up a column that adds the total costs and the total savings per year ("C1" = "A1" - "B1", "C2" = "A2" - B2", etc...).
4) Click on the cell where you want your IRR calculated
5) Enter "=IRR(" (without the quotes) and then highlight the total costs + total savings column and hit enter.
Just a comment that IRR for investments is a misleading figure. The discount rate that we use is lower than the IRR. The correct justification would be to look at NPV. Net Present Value.
Some look at payback period.
Some lookat IRR
Some look at NPV.
I think NPV is more accurate for Investment analysis.