What's a safe amount of leverage and reserves?

[Noah McPherson]

Hey BP, 

I have two questions I think would be important for me, as a real estate newb, to have a better understanding of. First, at what point would you consider a person Overleveraged? would you judge if a person is overleveraged by their income their bringing in and/or how much liquid assets they have in banks, mutual funds, etc.? Secondly, I would like to know how much I should keep in reserves? For example, I have a duplex. How do I calculate the amount of reserves I need? I understand the answer is probably subjective, but I think this is an important topic, as it keeps your portfolio in a safe position.