Have you ever heard the saying "It takes money to make money"? While there may be a handful of exceptions, for the most part the premise is true.

It's not true as true as some people think it is, however. Many would-be investors fear their monetary goals for the future are so far out of reach that they don't even bother trying to reach them.

Don't fall into that trap! Turning even a modest amount of money into a small (or even a large) fortune is more achievable than you might think. The key is simply using all the time you have left to grow a portfolio, and making a commitment to coming up with at least some seed money to put toward the effort. Even a feat like turning $10,000 into $100,000 isn't out of the question.

Time is on your side

Sounds too good to be true? Admittedly, a tenfold return isn't something you see or hear about very often. It's actually happening quite often, however. It's just that many investors don't realize it when it's happened to them, since they've been investing for so long, adding new money to their savings the whole time. 

The graphic below tells the tale. Assuming you're investing $10,000 into a market-based instrument like an S&P 500 (^GSPC 2.01%) index fund within a tax-deferring account and achieving its average annual growth of 10% on your investment, after 25 years you'll be sitting on a stash of a little more than $100,000.

Chart showing compounded investment returns on the S&P 500 growing from $10,000 to $100,000 in 25 years.

Data source: Calculator.net. Chart by author.

Surprised? Don't be. The magic of compounding isn't magical at all. It's just basic math. The longer you remain in the market and reinvest your dividends and growth, the more you earn on your historical gains. For perspective, in the final year of the 25-year stretch in question above, the portfolio grew by nearly $10,000... returns equal to the amount of seed money put to work 25 years back.

And don't sweat it if you don't have $10,000 worth of idle cash to work with right now. If you can come up with just a few thousand bucks per year, you can still do pretty well for yourself.

In the scenario below, we're still investing in an S&P 500 index fund, and still making this investment within a tax-deferring IRA. But, rather than a one-time upfront commitment of $10,000, we're going to make regular annual investments of $2,000 for a period of 25 years. After 25 years you've put in a total $25,000, but at the end of that timeframe your portfolio will be worth a bit more than $100,000.

Chart illustrating how investing $1,000 per year in the S&P 500 for 25 years will build a $100,000 portfolio.

Data source: Calculator.net. Chart by author.

Again, this incredible growth represents the power of compounding and time.

Details to keep in mind

There are a few footnotes to add to the number-crunching.

First, while the S&P 500 may boast an average annual return of 10%, its actual yearly gains are all over the map. Sometimes it gains more than 20%. In other years it may gain less than 5%. It logs a full-year loss about once every four years, and as you know, some of those losses can be uncomfortably big... like this year's. Smart investors don't bail out just because things are getting tough. To reap the full benefit of compounding, you have to stay in the market even when it's uncomfortable to do so.

Second, while $100,000 is a considerably bigger figure than $10,000 today, $100,000 won't be nearly as impressive of a figure 25 years from now. Inflation perpetually chips away at a dollar's purchasing power. If you can feasibly invest more in the future, you certainly should.

Third, the above examples both assumed the gains are being made within a tax-deferred account like an IRA. Just know you'll be paying taxes on your withdrawals from those accounts when the time comes. They could be hefty sums, depending on your situation. Be sure to plan accordingly.

Nevertheless, investing for long-term growth is still well worth the trouble, and the stock market is still the best and most accessible means of outpacing the effect of inflation.

Just do it

Not everyone has $10,000 right now, of course, or perhaps you don't have 25 years left where you'll be able to make annual investments of $2,000. That's fine, though. The two models above are merely meant to illustrate the point that you can build a much bigger portfolio than you might believe is possible. The key is simply getting started now, even if that start will be meager. An investment regime can be tweaked, improved, or expanded as needed in the future.

Bottom line? Do something -- anything -- today to get your wealth-building ball rolling.