So to get "your number" take your materials total and multiply by 1.5 then use that as the base for your labor estimate.

Lease Agreements, Form 1007, or Form 1025When current lease agreements or market rents reported on Form 1007 or Form 1025 are used, the lender must calculate the rental income by multiplying the gross monthly rent(s) by 75%.

When you enter the address of a property and the number of bedrooms and baths, Rentometer calculates the rent by multiplying the average area $/SF by the square footage of the subject property.For example, if the average $/SF for 3-bedroom homes in an area is $1.10/SF, and the subject property has an area of 1,500 SF, then the estimated rent would be:1,500 SF x $1.10/SF = $1,650/MoThe problem is that Rentometer, et. al., does not take into account the specifics of a property.Property Specific ExamplesProximity to nuisances - Property A, which is located next to Interstate 15, will have a lower rental price compared to Property B, even if the physical attributes of the properties are the same.

A gross revenue multiplier?

Water is easy - bill divided by total occupants at property (count everyone even children) then for each unit multiply the result by the number of people living there.

Here's my calculator:  Determine what your weekly rent is going to be on the property and multiply it by 26. 

Things of course vary from one property to the next and if you multiply your units, you multiply the frequency of problems you have to solve.

Anyone that has ever read or communicated with a city, county or public regulatory authority can attest to the often frustrating and unclear answers that are received (think DMV) but multiply it by twelve when it has to do with sometimes illogical or biased short term rental permissions. 

Multiply that by 4-5 (for the 20-25% down payment) and you will know the size of your potential maximum purchase.  

Purchase price: $142,000,000 Cash invested: $25,000 Syndication deal on a large multifamily apartment complex in the Phoenix area15.5% IRR1.98x multiplier exit in 2-5 year time frame