You can read books about estimating and find calculators online, but the best way is just to do a couple projects and see how well you are doing.

I recently joined the community and I'm evaluating a property with the rental calculator tool.

If you are purchasing in cash, you need to basically do the calculations if it is worth it walk out now and lose the deposit or take the house as is and fix up what is needed.

View report*This link comes directly from our calculators, based on information input by the member who posted.

Of course, we're RE Investors and we take risks sometimes, but let these risks be calculated risks.

Please make sure you are educating yourself (let me know if you need a list of books) and does not miss-calculate the expenses. 

@Isadore Nelson why aren't you using the BiggerPocket Calculators?

I'm not very familiar with the BP calculator but I would certainly encourage everyone to get prequalified. 

In my state, owning an LLC is quite expensive (800/year), so the risk/reward calculation is a little more skewed, but still generally makes sense for larger MFR deals.The debate really heats up if you're talking about residential class (1-4 units) as there are material advantages to owning under your personal name.

@Blue Presley @Greg Scott covered everything, but if you don't believe him, go find an ROI spreadsheet for real estate and calculate all this for yourself.