How much leverage is too much?

[Zachary Miller]

Hey all. I have been reading this site for a little while now and have learned a ton. One thing that I have noticed is how many of the investors here seem to love to use leverage to allow them to purchase more properties. Now I admit that I am pretty conservative when it comes to my finances, but this sounds fairly risky to me (I completely understand how the math works out and why people do it though). Is there a metric that is typically suggested for how leveraged an investor should be at any given time?