Practicing Partnership Math

[Lindsey Kocher]

So we are looking at acquiring a 2 property, 7 door package for $350,000. HELOC for down payment at 8.5%. I'll attach link to the rental analysis below.

What I'm needing is better understanding of analyzing the different ways passive investors can contribute, and those related outcomes. For example, if there is 3-way even buy in at $22,000, what is the 5 yr ROI?

My thinking is..
(assumed cash flow for each year) + (profit at time of exit + initial investment) /(% of initial buy in) = return. I understand unused reserves is also included but much more variable and anything is icing on the cake! Return/time in investment = ROI

Is this correct for a high-level overview to present to otherwise inexperienced passive real estate investors?

Does there exist a "template" or calculator that would support this? 

PLEASE show me the way...

TIA!

https://www.biggerpockets.com/analysis/rentals/88b87661-d1c9...