Enter the cash flow values in a single column, with the initial investment as a negative number and later inflows as positive numbers
Select an empty cell where you want the IRR result to appear
Type `=IRR(range)` where `range` is the cell range containing the cash flows
Press Enter to calculate the internal rate of return
Format the result cell as Percentage if needed
If the cash flows occur at irregular intervals, use `=XIRR(values, dates)` instead
Ensure the cash flow range includes at least one negative and one positive value
If Excel returns an error, check that the cash flow signs and range are correct
Adjust the optional guess argument in `=IRR(range, guess)` if Excel has trouble finding a result