How to determine if I am over-leveraged

[Wilson Cheung]

Hi Everyone,

I am new to the BP forum and relatively new to real estate investing.  I currently have two investment rental properties generating positive cash flow.  My plan is to increase my portfolio to 10 properties in 2017 based on 20% down with 80% financed.  The properties will be diversified across the country so that if there is a downturn in any particular region, I can withstand it with positive the cash flow from the properties in other regions.  However, I am worried that if there is a nationwide downturn (as in 2008), I may be over-leveraged.

How do you know if you are over-leveraged?  What ratio / threshold do investors use to ensure that hey are not over-extended?