Car not is 5 %my school loan is 4My wife’s is 6I am following the avalanche method , and starting off with an initial snow ball off 559.I just started budgeting this month so that snowball will increase once the dust settles. 

Personally I like to try and determine how many man hours things might take and then multiply that by what a standard labor rate might be.

You can add up the 2017 rate and multiply it to the appraised value To get the amount you are looking for. http://hcad.org/property-search/real-property/real-property-search-by-address/

Quick and dirty... take gross rents per month, multiply times 12 months of a year, to get yearly gross income.Then subtract 50% for expenses, or if you want to work and manage the property yourself, including light maintainance(for free), subtract 40%.

Multiply that times 75%.  

You can get a good idea of the cost per sq. ft. and multiply that average number to the square footage of the property you're interested in.For example, if the triplex is 3500 sq. ft. and the average sq.ft. number for similar properties you've come up with is $100: 3500 X $100=$350,000.Of course, there are other factors such as lot size, year of build, etc.

Yeah, I actually gave them a break-down of what I was expecting based on a 10% API where I divided by 12, and then multiplied by 3. 

Either the appraiser will do this for you OR if there are existing lease agreements, those can give you the value.Then you must multiply the fair market value of all rents by 0.75.

If you're predictions are off and you buy a 9 unit, multiply the damage by 9.

The benefit of having a GC on the project is that you have 1 person to hold liable for cost and schedule; dealing with contractors it's not always pleasant so no need multiplying the effort.