Student loans are tough to pay off—and nobody knows that better,perhaps, than millennials.

Dragging that load of student loan debt behind themhandicaps them severely as they struggle to keep up with all theother expenses of daily living (including the attempt to save forretirement).

A new study from LIMRA Secure Retirement Institute hasquantified that handicap.

Millennials who owe $30,000 in student loans at the beginning oftheir working lives will end up with retirement accounts that are$325,000 lower by the time of retirement than peers who don't carrystudent loans.

But wait, it gets worse. A millennial with $50,000 in studentloan debt—not an unreasonable number, considering how much and howquickly these loans add up—will face retirement with close to$530,000 less than someone who has no loans.

So it should come as no surprise that millennials working onpaying back those loans aren't contributing to retirement accountsat the same rate as peers who don't have to worry about those easymonthly payments. Millennials without student loans, the researchfound, are 60 percent more likely to maximize their employer matchcompared with those who are paying education loans.

Of course, it's easier to save for retirement when you're notpaying off huge loans; your quality of life isn't quite so strippedof perks like dinners out or occasional vacations.

And that's another problem: millennials aren't willing to dowithout the little comforts of life, assuming they can afford themto begin with, just so that they can pay down loans and at the sametime save for retirement.

A Schwab Retirement Plan Services study found that millennialsaren't upping their savings rates ifit means cutting out those little treats.

They might be sorry someday, though.

NerdWallet also crunched the numbers on how muchstudent debt is costing millennials, and found that the class of2015 won't be able to afford to retire till they're 75—and thatcarrying an average load of $35,051 in student loan debt and taking10 years to pay it off will make them $684,474 poorer in retirementsavings over 50 years.