Variable Break Even Values - Spreadsheet - arrays

Question

I'm looking to figure out the break even variables for a variety of columns based on the following spreadsheet.
Locations have a set number of devices (column B) and transactions (column C) that occur.
I would like to figure out a formula for columns M-Q that would show the break evens for each of those columns.
I made the following adjustments to match these specific columns for "Location 1" as an example:
Calculated value M3 by updating the cell, C3, until E3 (variable) matched J3 (static).
Calculated value N3 by updating the cell, C3, until F3 (variable) matched K3 (static).
Calculated value O3 by updating the cell, B3, until J3 (variable) matched E3 (static).
Calculated value P3 by updating the cell, B22, until J3 (variable) matched E3 (static).
Was not able to figure out a simple way to figure out how many years it would take to match lane model (static) to the per stransaction model (variable).
I'd like the sheet to be dynamic meaning if I adjust any of the variable fields B3:B18, C3:C18, or B22:B24 that I would get the breakeven values in columns M-Q to update automatically.

Answer 1

I think that I've got part of the answer for you - still working on the rest.
Try these two formula, in M3 and N3.
Break Even Transactions in M3
=ArrayFormula((H3:H+I3:I)/$B$23)
Break Even Transactions 5 Yr in N3
=ArrayFormula(((H3:H+(5*I3:I))/5)/$B$23)
UPDATE
Joe, I think I have the remaining three formulas that you need. Please check the results to see that they make sense, but I believe that I have the correct logic in the formulas.
Note also that to help me follow the logic, I used named ranges for three variables, which you currently have in cells B22, B23, and B24. I find it increases the chance of errors if I mix up true data with different types of variables or constants, so I moved them off to the right in my sample sheet. Your B22 I named PerLicenseCost, B23 is PerTransCost, and B24 is MaintRate.
The new formulas are as follows:
Break Even Device Count
=ArrayFormula(ROUNDUP(((C3:C*PerTransCost)/(1+MaintRate))/PerLicenseCost))
Break Even Avg. License Fee
=ArrayFormula(((C3:C*PerTransCost)/(1 + MaintRate))/B3:B)
Break Even Years
= ArrayFormula(-1 * (B3:B * PerLicenseCost) / ((B3:B * PerLicenseCost * MaintRate) - (C3:C * PerTransCost)))
Note that for the Break Even Device Count, I used ROUNDUP on the result in the formula, so that it would not include a fraction of a device. You may not want this.
For the Break Even Years, there were four negative results. I'm hoping this means that those locations are losing money, and will never break even, but I'll let you review them and decide that.
Note also that you can easily modify these formulas to move them up into the header row (row 2), if you prefer. To do that, in the header of the desired column, copy the existing formula from the cell below WITHOUT the equal sign and paste in to the following:
={“ text header for the column “; PASTE CURRENT FORMULA HERE }
Be sure to then delete the formula in the cell below (in row 3) or you’ll have a #REF error. If you need any help with this, let me know.
Let me know if you have any questions about any of this. I’ll be happy to answer them, but possibly not for a day or two.