According to this living wage calculator http://livingwage.mit.edu/, the living wage for a family of 4 where I live (suburbs of DC) is about $50K. That sounds like a lot, but actually living here there is no way we could survive on that. They only calculate $464 a month for medical for a family of 4. I'm lucky in that my wife has ridiculous health insurance through her job. When we didn't have that our share of the premium was more than that, let alone copays, OTC drugs, etc. Also, the living wage calculation does not account for clothes, school, or about 50 other things that would come up in a family with kids.
Minimum of course, is $7.25.