Multiply the principal by the rate, then divide by 12.An amortizing loan is a lot harder to explain, but interest-only is pretty straightforward.

Instead, I have seen duplex investors focus on Cost-Per-Unit and/or Gross Rent Multipliers (GRM).For example, I just saw a duplex in a C area listed for $54,900 that has income of $1,100 total ($550 per side), which is $27,450 per unit or GRM of 50.  

Fast forward, 15 year later, now owning my own real estate auction company, created a ton of equity, earning more and able to multiply myself by training others to network and work for me. 

Take the square footage and multiply by X to get the offer dollar amount.Make sure you send at least 500 offers out like this.  

Multiply by 10% if the property is owner occupied residential, to reach the assessed value.

Work the numbers backwards:price should have been 10x the GSI  (the 10x is the GRM: Gross Rent Multiplier)so GSI = Price/10Divide by 12 = Gross Rents per month.

I am no expert but I would like to give my opinion, so for this deal to make sense I BELIVE you should ask for a higher rent for the family that is there already ,try to raise it by $ 100 more a month (and you been fair )and for the other unit on that area you should not have any issues of renting it for $ 900.Update the apt but don't go and spend a lot as long as is in a good living conditions (if you update it you should get more rent so you can get your money back quicker )And you should meet your 2% rent on a price base on Brandon of BP 75,000 multiply by 2% =$ 1500/monthly rent 750+900=1650 1650 multiply by 12 months =$ 19,800/year10,000 loan payment for the year you left with 9,800 -other expenses =net profit Good luck

Multiply that times .70 and that will be the most that a seasoned investor is willing to pay for the property, so $70K.  

There are so many multipliers and formulas used to evaluate a deal.  

The information in the table includes the basic statistics - beds/baths, total square feet, $/sqf - driving towards an average $/sqf that is multiplied by our ARV sqf to equal the proposed ARV.