What to offer on a triplex...

[Jonny Morris]

Evening all, 

I am getting lost in NOI and Cap rates. What is the formula or points of reference to calculate investing in a multi-family?

Can I work backwards from a projected rent? Lets say each door rented for $700. It would generate $2,100 per month. Tentatively estimate (for convenience) the 50% rule for expenses. Plus mortgage. Im left with cashflow. Obviously, how much I throw down for deposit and rehab would allow me to calculate the ROI.

I would like to BRRRR but am aware that being a multi-family it would be appraised by either market value or income.

Can someone slap some stone cold formulas or knowledge down please?