How do I change the sign of a base number for use in XIRR?

[Guest]

I want to use the XIRR function to calculate compound growth rate. You have
to change the sign of the base year and I don't know how to do it in a
formula. Please help.

 

[Guest]

Since the argument for the XIRR function cashflows is a range, I do not think
you can change the sign on a single value of the range. The easiest way to
proceed is to enter a negative number for the first year's cash flow:

1/1/2006 -100
1/1/2007 50
1/1/2008 40
1/1/2009 80

Regards...