Its the age-old question: How much should I save for retirement?

For years, financial advisors recommended people save at least $1 million to enjoy a comfortable retirement. But given longer lifespans and concerns about the financial status of Social Security, is that target enough to fund a potentially decades-long retirement?

Maybe not.

Well-off investors surveyed by asset manager Legg Mason in March said that they would need at least $2.5 million to maintain their lifestyles in retirement. And a recent survey by the Employee Benefits Research Institute found more than 1 in 10 workers overall think theyll need to save at least $1.5 million to retire comfortably.

On the other hand, 69 percent in the same EBRI survey thought theyd need to have less than $1 million by retirement--and 1 in 5 thought theyd need to save $250,000 to $499,999. (Even that is more than what many retirees have actually saved. The average retirement savings is about $104,000 for households with members ages 55 to 64 and $148,000 for households with members 65 to 74 years old, according to an analysis by the Government Accountability Office.)