Rental housing costs vary across the state, but there is no place where it's affordable to someone earning the minimum wage of $8.25 an hour.
Bob Palmer, Policy Director for Housing Action Illinois, said the numbers show a problem that can lead to more homelessness.
"But for most people, what they do is they just wind up spending a high percentage of their income on rent,” he said. “If you're an extremely low income household, chances are you're probably paying in excess of 50 percent of your income just to keep a roof over your head."
Palmer said the situation has worsened since the foreclosure crisis.
"There's been an uptick in the percentage of all households who are renters and that's essentially created more competition for rental units," he said.
Palmer said a tight rental market is making the situation worse as costs are going up. In rural areas, what's known as the housing wage on average is over $12.50 an hour for a modest two bedroom apartment. It's nearly double that in the Chicago area. Palmer's group is pushing for a minimum wage increase.