Some people just kind of pretend the higher mortgage payment is in the past, and just do their math on the future property and not on the net cashflow situation. 

When I do that math on estimated rehab and ARV, the 50% of profit doesn't even equal the 20% mark up of construction costs that I should be getting paid to run my business.

Do not cut any corners on a prospective deal to make it look better.Always do the math analysis and try to look at the prospective property before you submit an offer or at least have a clause in the sales contract that allows you some time (about 10 days) to make a detailed inspection without having a penalty that will hurt you too much.  

If you can find a local lender that'll review your paperwork, run your numbers, and show you their math, you're doing pretty good.

My name is Shea And In anxious to start and begin in Realestate investing, Creating Positive Cash Flow but most importantly building wealth & finacial freedom, But first want to Master the Math and Analysis of Properties.

The math on SFHs simply does not add up unless you are speculating in a very high appreciation market.

I'm a recent college graduate with a degree in math and economics. 

The home you live in is NOT an investment...it is however your biggest cost.This is a simple math problem.If you put money in a property and leave it there, it is a negative number = Your cashIf you get money out of a project, it is a positive number = your profit or cash flowIf someone else puts the money in a project, it doesn't count as positive or negative = leveraged funds...unless, you have to pay for those funds = loan interest.However, if someone else pays for those "interest costs", they don't count as positive or negative = Cash flowJust apply all the cash moving in and out of your deal(s) to one of the above definitions, add (or subtract) all the numbers as indicated above, and you will see either a total that is positive...or negative.If it's positive, you are making money.  

I'm starting to get a general idea of how I should look for a property that would be good to purchase, renovate, then rent out. I'm a little lost on which formulas I should use when considering a property. Things like...

You learned your lesson.She is brave to push you like that when you have more power in this relationship in the long run.Put some sod in, do the math on that.Even if it is only a small patch of sod, it could meet the definition described in the email.