Sobering fact for the millennials out there: according to a new study, the average student loan debt of $35,000 can cost graduates nearly $700,000 in lost retirement savings over a 50-year period.

What’s that mean in real terms? If a 23-year-old earning the median salary, who has $35,000 in student debt, can only manage to save 6 percent annually because he has to pay back his loan, he can expect to retire at 75. Without the loan, he might easily manage to increase that savings to 10 percent annually, and the retirement age drops by five years.

The average student debt is now $5,500 higher than it was just three years ago. If that rise isn't somehow slowed, the student loan crisis will become a retirement crisis.