The formula goes like this Gross Rents X.75% minus your PITI = profit or (loss).

@Peter Nikic What you have provided is the formula for calculating revenue per month. 

The formula for calculating the annual maintenance provision for a component is below.Annual Maintenance Provision = Replacement Cost / Remaining Useful LifeOrAnnual maintenance provision = $900 / 7 Yrs = $129/Yr. or $11/Mo.You can do a similar calculation for all the major components of your property.

I am a complete newb that just finished up a 3 day Formula Flipping seminar in Orlando and very excited to get this off the ground.

I want to add that the ROI formula is looking also at the amount of money out of pocket invested in the project so if you leverage the investment with debt of any kind you will increase your ROI, as long you give it back...

You would really need to come up with your own formula for your investing strategy.If the owner pays the back taxes, you will get the interest that the county charges for the lien--that interest will vary between each county.Not sure about the ratio...but I think a lot get redeemed.Good luck and I might ask you questions about GA as I believe it is a deed state.Thanks!

Pay the bill yourself, then reimburse yourself by charging the tenants based on a formula.

Since each situation is different, it's going to be difficult to provide a formula for successful percentage off list.

I found this cap rate formula useful if you are in a hurry.

The benefit of preserving the facade through The L'Enfant Trust's Historic At least three or 4 math questions using the different formulas in the guideQuestion regarding the condo conversion fee.