Sixty-one percent of Americans are unaware of how much savings they will need to successfully retire, Bankrate.com learned in a survey. The median amount among those who have assessed how much they will need is $650,000. Nineteen million Americans say they never plan to retire, including 9% of both Millennials (18- through 37-year-olds) and Baby Boomers (54- through 72-year-olds).

Millennials are the most apt to be unsure of how much money they will need, cited by 69%. However, even older Americans are not in much better shape vis-à-vis retirement estimates: 56% of Generation X (38- through 53-year-olds), 58% of Baby Boomers, and 59% of those 73 and older have no clue.

Among people who have put some thought into the required retirement savings, responses are all over the map, with 7% saying between $250,000 and $500,000. Eight percent each say $250,000 or less, $500,000 to $1 million, or more than $1 million.

Gen Xers are twice as likely as any other age group to say they will need over $1 million to retire. Those who are working are three times as apt to say this, compared with those who are not working. Additionally, people who live in the Northeast (12%) and West (11%) are twice as likely to say $1 million or more than residents of the Midwest (5%) and South (6%).

“The key to retirement savings is to actually save for retirement,” says Bankrate.com analyst Taylor Tepper. “Put away at least 10% of your pay, including any employer contributions, into your retirement account—and do it yesterday. There are pretty sophisticated online calculators and tools that can help you estimate how much you’re going to need, and you can always hire a fee-only certified financial planner if you want a little more hand-holding.”

More than half of Americans say they have sought advice on retirement planning. Twenty-six percent consulted a personal financial adviser, and 21% asked a family member or friend. Eleven percent used an online retirement calculator, 10% reached out to a bank or financial institution, 8% relied on expert commentary or articles, and less than 1% used a robo-adviser.

Millennials are the most apt to reach out to a family member or friend (30%), while Boomers are the most apt to work with an adviser (37%). People who are married or living with a partner are twice as likely to consult a personal financial adviser or financial institution than those who are single or living alone.

Asked how much of their retirement would be funded by Social Security, 61% said little to none, 20% said half, and 17% said most of their income would be from Social Security. “Social Security will almost certainly contribute a sizable portion of your retirement income, even for Millennials, despite erroneous declarations that the pension program will soon go bankrupt,” Taylor says.

GfK Custom Research North America conducted the survey among 1,000 adults for Bankrate.com in May. The survey can be viewed here.