I just finished Avery Carl's book on Short Term investing and see the Gross Rent Multiplier formula as well as the Cash-on-Cash return formula.

. - find a formula that works for you and start making offers.  

It wouldn't surprise me if sites like RENAV just work the amortization formula based on the last loan and terms.

If you are looking for a quick method to provide a ballpark estimate, there is an easy formula. 

@Jacob Abuata congrats on what you've done so far.If you want 10k/mo (120k/yr) in passive income the formula is pretty easy (but no so simple to execute).

But we have looked at many other properties using the same formulas and every time, our offer price calculation is significantly below asking price. 

I am just starting out and I have recently found a house on the MLS that is a duplex which needs some work but it is selling for 99,000 and has 1 existing long term tenant already paying rent of 825 per month.2 questions:1) What is the exact formula or guide i can use to analyze this house (Duplex) to see if it is a good investment as a rental property? 

Lekisha,If you can buy at a deep enough discount where the basic formula still applies (70% of ARV minus cost of repairs) and you can still sell at a profit after Realtor commissions, that's what matters.Gary

Same question for cash-on-cash formulas.

@kevin zheng    I'm not sure of their exact formula, and whait I'm about to say may be a conincidence because  I have Section 8 rentals in Cleveland as well as Concord, CA and Oakland, CA.