So, you have no idea how much you should save for retirement? Join the club.
Eighty-one percent of Americans said they don't know how much money they'll need to fund their golden years, according to a new survey of retirement readiness from Bank of America Merrill Lynch.
"It's a complex thing to calculate. You have to make four or five assumptions to get to an answer," said Geoff Sanzenbacher, an economist at Boston College's Center for Retirement Research.
One of the biggest unknowns is determining how long you will live. Among the 4,854 people questioned in the survey in August, the average person said they expected to live until age 90.
That's a 20-plus-year retirement if people leave work when they qualify for full Social Security retirement benefits.
However, only 16 percent of those age 50 or older said they could fund a retirement lasting 20 years. That figure rises to just 27 percent if those 50 and older were to prepare for a 10-year retirement.