NPV Formula

Without putting much thought into it, my first thought is to use Solver (Goal Seek also might work). Call Solver and tell it to:

1) Set Target Cell: C5
2) To a value of: -300000
3) By changing: J3

That would work for one time or occasional solutions. With additional thought, the NPV function [NPV=sum(for i=1 to n)(value(i)/(1+rate)^i)] should be easily (if tediously) solved algebraically for any one of the values. If this is a frequent task, I would spend some time with the algebra of the problem and come up with that solution.

If I understand correctly, then use the Goal Seek Function on the Data Tab, Forecast, What-If

Capture.JPG

EDIT: I got it backwards. MrShorty is on target. Left up so you can see picture of Goal Seek

@warshad.... It is unclear how general a solution that you want. For what you have in stated in the example, enter the following into J3:

=(-300000 - NPV(0.08,G5:I5,J2,K5:M5)) * (1+0.08)^4

Explanation.... This is based on the mathematical equation for the NPV, to wit:

-300000 = G5/(1+0.08) +...+ I5/(1+0.08)^3 + (J2+J3)/(1+0.08)^4 + K5/(1+0.08)^5 +...+ M5/(1+0.08)^7

Solve for J3 algebraically.

PS: Of course, 1+0.08 could be written 1.08. I write 1+0.08 in anticipation of recommended design change, to wit: put 0.08 into B5, and write 1+B5.