There's a reason working Americans are urged to start saving for retirement as early on in their careers as possible. Thanks to the power of compounding, the more time you give your money to grow, the more you stand to accumulate. Yet a frightening number of Americans aren't heeding this advice. According to a 2015 report by the U.S. Government Accountability Office, almost 50% of households age 55 and over have absolutely no retirement savings whatsoever.

If you're in your 50s (or worse yet, your 60s) and have yet to start putting money aside for the future, you should know that it's not too late to catch up -- but you will need to start employing some smart savings strategies immediately. Here, we'll review some last-minute retirement savings tips and show you how even a few years of compound interest can work wonders for your nest egg.

Senior couple looking serious while talking to a financial advisor

IMAGE SOURCE: GETTY IMAGES.

Start slashing expenses

If you're serious about getting a jump on your retirement savings, one of the first things you'll need to do is review your budget and find ways to cut corners. This might mean downgrading your cable plan, canceling your gym membership, or skipping your weekly restaurant dinner in favor of a home-cooked meal. All of these little changes can work to free up cash, which can then go directly into savings.

If small changes don't make enough of a dent, you'll need to start looking at bigger lifestyle adjustments. That second car you enjoy having? Getting rid of it might put thousands back in your pocket. You might even consider downsizing your living space if doing so frees up enough cash to help make up for lost time.

Save your raises and bonuses

Given the number of Americans living paycheck to paycheck, there's a good chance the bulk of your income is already spoken for. But if you pledge to put any extra income you receive directly into savings, it'll help your catch-up efforts tremendously. The next time you get a performance bonus, cash gift, or even a tax refund, take that money and put it into your 401(k) or IRA.

Consider a side job

If your regular earnings don't allow for much savings, and there's really no wiggle room in your budget, then your next best solution to your savings problem could be to get a second job, even if temporarily. And you don't need to spend your nights and weekends waiting tables or bagging groceries to bring in that extra cash. You can try moonlighting as a consultant in your current field (provided there's nothing in your primary employment agreement barring you from doing so), or turning a hobby (say, your love of playing piano) into an income-producing gig.

Work longer

It's natural to have a specific age in mind for retirement, but if you're behind on savings, you'll need to be flexible about when you end your career. The longer you work, the more opportunity you'll have to sock away the money you should've been saving earlier. Currently, workers 50 and over can contribute up to $24,000 a year to a 401(k) and $6,500 a year to an IRA. Maxing out the lower of these two options for 10 years will give you an extra $85,000 for retirement if you invest that money and bring in a relatively conservative average annual 6% return.

Another thing to keep in mind is that the longer you work, the later you'll first start dipping into your savings. And funding a 20-year retirement, for example, will be easier than funding one that's 24 years in length.

Establish your savings goal and set your priorities

Even if you're starting late on retirement savings, you still have plenty of opportunities to amass a nest egg. To stay motivated, and on track, spend some time mapping out a retirement budget so that you get a sense of how much money you'll actually need. It's often easier to work toward a specific goal rather than just start arbitrarily putting money aside with no particular target in sight.

You can use this handy calculator to figure out how much you should be saving:

 

* Calculator is for estimation purposes only, and is not financial planning or advice. As with any tool, it is only as accurate as the assumptions it makes and the data it has, and should not be relied on as a substitute for a financial advisor or a tax professional.

To use this tool, simply plug in your current age, desired retirement age, and the amount of income you think you'll need to sustain yourself as a senior. From there, it's a simple matter of seeing how much you need to save each month or year to meet your goal. Just as importantly, this calculator will also show you how much more you'll need to set aside each month or year if you delay your savings efforts even longer.

While catching up on retirement savings might seem impossible, if you make it a priority, there's a good chance you'll manage to compensate for your late start. 

The Motley Fool has a disclosure policy.