To calculate the ROI of a property, an investor needs to know:Estimate annual rental income -- including tenant rent and additional income like pet rentEstimate annual operating expenses including repairs, property management fees, insurance, and taxesForecast annual cash flow by subtracting expenses from incomeDetermine down payment and other upfront cash (such as needed repairs)Calculate ROI by dividing annual cash flow by the total amount of cash invested3.

I was wondering how much to subtract off the arv for each comp that has a extra bedroom, bathroom or above or lower then my the square feet range?

Here are the numbers:Purchased in October 2019: $360,000 (not renovated)Current list price: $345,000 (initial list price $395,000 on 4/26)Mortgage left: $267,794 (before I make the August payment)Monthly payment: $1687 (includes insurance and property tax)HOA fee: $605 a month My renovation costs: $17,726 (already paid off over 2 years ago)The renovations realtor had done recently: $11,742 (to be subtracted from the sale or I pay the renovation company that amount within a year)There was a special assessment last year of $1600 for elevator repair.

Now, when you sell you do have some closing costs, so subtract those out, and that will give you are true cash-on-cash return.I hope all of that makes sense.  

You need to add principle paydown to your income and not subtract your mortgage payment. 

Subtract 40% for expenses (expenses can range from 35-50% depending on the park and the amenities, but for this example we will use 40%)  and you are left with $22,680 which is the NOI. 

So when I see final cash flow, I have to subtract the debt service payment going to the HELOC.

I manage several properties where we have the tenants take a photo of the meter each month, showing the reading, so that we can then bill them appropriately by subtracting their usage from the main meter.

Send the deposit refund as required after subtracting whatever charges are deductible/chargeable against the deposit.

If you have a lease at $3,000/month, the lender will only count 75% of that income and then subtract it from the PITI.