Forum Discussion
Payback Period
In my file, how should I adjust my payback period formula so it "always correct", in that it always uses the correct formula as in the year it is not negative for the cumulative cash flow row? Is th...
Your formulas look good overall just a few tweaks Payback Period - Instead of hardcoding use a lookup on cumulative cash flow to find the first period where value is greater than or equal to zero then interpolate for months That way it is always correct NPV - Use NPV rate C34 to G34 plus B34 to avoid double counting and keep it clean IRR - Your formula is fine as long as B34 is the initial outflow ROI - Looks okay just confirm inflows are positive and outflows negative That should give you a solid sanity check