IRR ( values [ , [ guess ] ] )

Description: Computes the internal rate of return for a series of cash flows represented by the numbers in values. (These cash flows do not have to be even, as they would be for an annuity. However, the cash flows shall occur at regular intervals, such as monthly or annually. The internal rate of return is the interest rate received for an investment consisting of payments (negative values) and income (positive values) that occur at regular periods.) IRR uses an iterative calculation technique.

Arguments:

Name	Type	Description
values	array, reference, text, logical	The set of numbers for which the internal rate of return is to be calculated. values shall contain at least one positive value and one negative value to calculate the internal rate of return. The order of numbers in values is significant, so be sure payment and income numbers are in the desired sequence. If values contains elements that are text, logical values, or empty cells, those elements are ignored.
guess	number	An estimate of the result of IRR. If omitted, it is assumed to be 0.1 (i.e., 10 percent).

Return Type and Value: number – The internal rate of return for a series of cash flows.

However, if the calculation has not converged after an implementation-defined number of iterations, #NUM! is returned.

[Example:

IRR({-70000,12000,15000,18000,21000}) results in -2.1245%
IRR({-70000,12000,15000,18000,21000,26000}) results in 8.6631%
IRR({-70000,12000,15000},-0.1) results in -44.3507%

end example]