Math- find your NOI then work backwards to see if it cash flows and what you can borrower money at to not kill the deal. 

You’ve clearly done your homework and are approaching this with the kind of long-term, strategic thinking that sets great investors apart.House hacking is a smart entry point, especially in a high-barrier market like NYC.

A few quick do’s and don’ts from my experience:Do’s:- Do your homework on local zoning and licensing requirements early, it saves a ton of time.- Do build relationships with the right professionals.- Do run conservative numbers so you’re prepared for any surprises.Don’ts:- Don’t skip due diligence just because the deal looks good on paper.- Don’t underestimate the importance of solid systems and tenant screening, it makes or breaks operations.- Don’t try to do everything yourself; having a good team matters.Every market has its nuances, but those basics apply everywhere.

They either commute or work out of their home. 

Math.

Anyone have a simple way to calculate ROI for the first year for a rental property? In other words is this a good formula (cash on cash return % + 3% appreciation + 2% tax benefits + 2% amortization)? I don't know...T...

Here's some math: if we have a property with an income of $1.2 million, and we subtract 50% for expenses (because, hey, life happens), we're left with $600K in net operating income (NOI).

It’s part math, part art; Danilo I really hope this helps you a bit...

It's also a good idea to do your homework on who you end up doing novations with as well. .Your comment: "To prevent it: record a memo against title and include clear remedies if seller defaults.

@Chris Forbush isn't wrong if you think you'll need a property manager/cohost, but if you've done you're homework then you can absolutely run an STR on your own from a distance.