What is Overleveraged?

[Jason V.]

This thread is inspired by an ongoing debate: Possible to grow without debt?

My question isn't whether I should use debt or not - it's how to know when I am over-leveraged. 

I know there is a degree of personal "feel" to this, but I'm looking for a way to even put a number to it. I think it would be a factor of cashflow, equity, and reserves, but there seems to be a very clever and helpful way to calculate everything in REI already - I just haven't seen anyone talk about this.