Let me preface this forum post by saying that no one is an actual dummy when first starting out, but to grab your attention I had to use something good :) Cap rates, gross rent multipliers, cash on cash return, internal rate of return, ROI, 1% rule, and the list goes on in terms of underwriting calculations you must know as an investor.

Now, multiply this by 100... 100 of us have found 100 deals, made 100 improvements, and raised 100 property values. 

I'm doing $75 per sg ft and multiply that by 15% for some safe zone.

@Ali AhmedYes there is a formula; you take the anticipated rent increase, in your example we will assume $500 for the math, and multiply by 12 (returns are always calculated annually); take that number and divide it by the cost of the project ($10,000) and you get your ROI (return on Investment).Formula is: annual increase / project cost = ROINow, you have to decide what return is worth it for you to undertake the project.

@Brady MullenIn real estate, debt is a multiplier of effectiveness.  

Multiply that by 100, and that's what I can afford to pay to buy and renovate the duplex.

Even in 1970 during high rate of inflations, the growth multiplier of RE is 3.x ; more than the average of 1.5%- If you compare to actual hyper-inflation in developing country, gozzz, this is nothing.

Ideally want to start out with 500 Direct Mailers every two weeks and some Bandit signs/Car Magnets.Not enough, you need to multiply those numbers by 10 and hire 20 people to call for you. 

I would just multiply that amount by the number of months that were late. 

If you are new to flipping, the good rule of thumb is whatever your renovation estimate is, multiply it by 2 and that's your real number.