Help - useful rental property analysis?

[Fred A Baugh]

Hello,

I am interested in 1031 exchanging four of my duplexes in California into an apartment building in Idaho.  I am having a hard time running the numbers to determine if the apartment is a good investment.  I have all the 2018 income and expense worksheets, but they seem to make things more complicated and confusing to compare.  I would like to use a simple cash flow vs investment to make an apples to apples comparison.  It is reasonable to say:

Apartment Annual Income = $491k

Apartment Annual Expense = $188k

Apartment Annual Net Income = $303k

Apartment Cost = $4M

Apartment Downpayment = $3.2M

Apartment ROI = $303k/$3.2M = 9.5%

Then I can do the same thing with the duplexes but dividing my (Annual Net Income) / (Duplex Equity) to get the ROI on my current investment.

Is this simple approach a reasonable way to assess this purchase?  

I didn't include the mortgage expense yet because I am not sure how to account for it.  Do I subtract out only the annual interest payment, or the entire payment including principal and interest?

Thank you for any input.