Estimating profit on a rehab

[Douglas Curtiss]

I’m in the process of trying to reverse-engineer my financial freedom number - starting with a goal of making X dollars per year, then figuring out how many rentals or flips or wholesale deals to reach that number. I know @Brandon Turner has a general rule of thumb of $100 per door per month profit for renting small multi families.  

I’m wondering if there is a similar rule of thumb for flips. I know that the numbers vary from deal to deal, but I’d like to have a general idea of how much profit to expect from a flip (on a cash-on-cash % basis) so that I can conservatively estimate how many flips it would take to reach my final number.