@Edward Pulido - In your example you would be into the deal for purchase + rehab totaling $150K. The ARV is estimated at $190K. When you go to do a cash out refinance the most you'll get is typically (may be higher but lets be conservative) 70% of the LTV (in this case it is the Loan to ARV) back. 70% of the $190K is $133K. If this is the case you will be short $17K. If you are able to refianance at 80$ of Loan to ARV then you'll get to the $152 as you and @Darren Budahn mentioned.
In order to get your full $150K back and move to the next property you'd have to be selling at $214,285 or hope to get to the $80K Loan to ARV.... and be certain that ARV is correct.
Personally for me and full disclosure I am new to investing myself, getting the ARV is the scariest part. Most all of the rest of the investing equation is pretty straight forward but make sure you get the ARV correct. I would also get your financing worked out before you bought the property. Talk to the banks, credit unions, mortgage companies etc... ahead of time. Ask them about their refinance options and find one ahead of time that will work with you. If not have a plan B, a different exit strategy should you not be able to refinance. A word of caution - I have heard (could be wrong) that some institutions, when they hear you are rehabbing will only give you 70%-80% based on your initial purchase price + rehab costs. I have not personally been told that by a lender but I have heard that at a couple of REIAs.
I hope this helps. Good luck.
Regards,
Todd
p.s. BP has their BRRRR calculator you can use HERE. Or if you want to work with spreadsheets you will find a couple uploaded by fellow BP members in File Place here on the site.