When it comes to finances, Americans have a lot to be anxious about. The typical household is $16,000 deep in credit card debt, while 57% of U.S. adults have less than $1,000 in the bank. But it's not spiraling debt or unplanned expenses that have Americans worried the most. Rather, their single greatest collective fear is never being able to retire. That's the latest from GOBankingRates, but it also represents a shift from the previous year, when Americans cited always having to live paycheck-to-paycheck as their primary financial concern.

So what changed?

It could be the fact that Americans are doing a slightly better job of saving money for the near term, even though most adults are still behind where they should be. Or it could be that Americans are getting more realistic about retirement and the costs involved. Either way, those who fear never actually retiring should realize that they do have an opportunity to change their fate -- as long as they get moving quickly.

Man sitting with a laptop, cupping his own cheek and holding a cup

IMAGE SOURCE: GETTY IMAGES.

Salvaging your retirement

It's no secret that most Americans are behind on retirement savings. The median savings balance among workers in their mid-to-late 40s, for example, is just $6,200, which is nowhere near the amount folks that age should have in their nest egg. (You should have roughly four times your salary saved up by then.) Furthermore, while some workers may be inclined to fall back on Social Security in the absence of independent savings, those benefits won't be enough to cover the bills in retirement, no matter how frugal a lifestyle you're willing to live. The average recipient today gets just $16,320 a year in benefits -- hardly enough to survive on.

Even with all that said, if you're sorely behind on savings but still have a number of working years ahead of you, there's no reason you can't catch up. And you don't need to set aside an unrealistic sum of money each month to do it. That's because if you give yourself a wide enough window of time, you'll get to take advantage of compounding and turn a series of smaller contributions into a more substantial sum over time.

Check out the following table, which shows how much of a nest egg you stand to acquire if you set aside just $300 a month starting at various points throughout your career:

If You Start Saving $300 a Month at Age:

Here's What You'll Have by Age 65 (Assumes an Average Annual 8% Return):

25

$932,000

30

$620,000

35

$408,000

40

$263,000

45

$165,000

TABLE AND CALCULATIONS BY AUTHOR.

As you can see, if you give yourself a 40-year savings window by funding your nest egg starting at age 25, you'll turn a total of $144,000 in out-of-pocket contributions ($300 a month x 40 years) into a whopping $932,000. That's a $788,000 gain, which is pretty hard to beat, and while it does rely on a stock-heavy investing strategy, that's a reasonable approach for anyone who's 10 years or more away from retirement.

Of course, you can't help but notice that the longer you wait to start funding your nest egg, the less compounding will work to your benefit. For example, if you don't save a dime until age 45, but put $300 a month into a retirement for the next 20 years, you'll end up contributing $72,000 of your own money, but you'll only be looking at a $93,000 gain. Is that a small number? No, not at all. But it's also not nearly as impressive as snagging an extra $788,000.

And while $932,000 constitutes a healthy nest egg, $165,000 won't buy you much financial security as a senior. So if you're still relatively young and have an opportunity to start funding your retirement account(s), then don't wait a minute longer.

It's never too late

If you're an older worker approaching retirement, you may be reading this, burying your head in your hands, and giving up on the idea of ever leaving the workforce. But not so fast -- even if you don't have a huge savings window ahead of you, you still have a shot at a secure retirement if you change your ways immediately.

For one thing, start saving every extra dollar you bring in, and if your paychecks don't allow for that, get a second job. It's not ideal, but it beats better working well into your 70s or 80s. Workers aged 53 to 62 who take on a second job are more likely to bring home an extra $1,000 a month than any other age group. Put $12,000 a year into your 401(k) for five years, and even with a conservative 5% return, you'll still be looking at $66,000. That, combined with Social Security income and additional funds you might be saving, could enable you to retire fully at some point down the line.

It's easy enough to worry about retirement and how to pay for it, but rather than lying awake at night stressing over the future, make changes to your lifestyle now so that you can ramp up your savings efforts. You don't need to max out your 401(k) starting at age 22 to enjoy a comfortable retirement; you just need to start early enough, or take steps later in life that allow you to compensate.