Americans expect to have a quarter of a million dollars saved by retirement, according to a 2018 survey from Provision Living. In an ideal world, though, the 2,000 survey respondents said they would want decidedly more: an average of about $610,000.

Unfortunately, that may not be enough: Depending on where you live, you could blow through even $1 million as a retiree in as little as 12 years, according to a 2018 report from personal finance site GOBankingRates. And GBR notes that, since the average person retires at age 63 and has a life expectancy of about 85, "Americans should plan to spend 22 years in retirement."

The survey notes that, currently, 43 percent of millennials have under $5,000 in retirement savings.

How do you know how much money you need for your golden years? The answer is highly personal and depends on your lifestyle and spending habits, but there are a few basic guidelines to follow if you want to retire comfortably.

For starters, many experts, including co-founder of AE Wealth Management David Bach, say that if you set aside at least 10 percent of your income, you'll be fine. More is better: Bach adds that if you want to retire "rich," save 15 to 20 percent and, if you want to retire early, save 20 percent or more.