Thanks, I wanted that and just used it. I then realized you could also manually calculate XIRR using Goal Seek. Suppose your dates are in D2:D100 and values i

Thanks, I wanted that and just used it. I then realized you could also manually calculate XIRR using Goal Seek. Suppose your dates are in D2:D100 and values in V2:V100. Add a cell, let's say I1, to hold an interest rate value, and another column W with formulas defined as follows (filled downward from W2): =$V2*(1+$I$1)^(($D$100-$D2)/365) Then make a cell J1 with formula =SUM(W2:W100). Run Goal Seek to find the value of I1 which sets J1 to the value 0. This will give you XIRR. (At least for non-leap years. I'm not sure how leap year logic works.)