Most of us, unless we're billionaires, want to be millionaires. It's very possible to become a millionaire, too, if you have a few things going for you -- such as determination, the ability to keep investing money regularly, and ample time.

Here's a look at some actions you can take if you'd like to achieve millionairehood -- for those who are in a hurry and those who are not.

Someone is looking at the camera with a finger on his temple.

Image source: Getty Images.

If you want to become a millionaire -- eventually

If you're still relatively young and can stay focused on the goal of amassing a million dollars (or more!), you can probably get there. Check out the table below:

Growing at 8% for

$7,000 invested annually

$15,000 invested annually

5 years

$44,351

$95,039

10 years

$109,518

$234,682

15 years

$205,270

$439,864

20 years

$345,960

$741,344

25 years

$552,681

$1,184,316

30 years

$856,421

$1,835,188

35 years

$1,302,715

$2,791,532

40 years

$1,958,467

$4,196,716

Data source: Calculations by author.

You can achieve millionairehood over 35 years simply by socking away $7,000 annually (which amounts to around $600 per month) and earning an average annual return of 8%. (The stock market's long-term average growth rate is around 10% per year, but over your years or decades, it might be more or less.)

So if you start in earnest at age 30, for example, you might have a million dollars or more by age 65, a decent age at which you might retire. If you're able to sock away $15,000 annually (about $1,250 per month), you might get there a decade earlier -- by age 55. Starting early can help you achieve an early retirement.

Either way, though, those are very long periods. You will have to trust that long-term investing works and you'll have to keep at it. In your first years, your money probably won't look like it's growing very much. Maybe you'll gain $5,000 or $10,000 over a year. But 20 years later, you might see your nest egg growing by $100,000 or $200,000 over the course of a year.

If you want to become a millionaire as soon as possible

Let's say you don't have 25 or 35 years in which to save and invest for retirement, though. Or maybe you're just 25 and you don't want the process to take 25 or 35 years. You might still achieve millionairehood -- by being more aggressive.

Here are five smart moves you might make:

Invest aggressively

If you can sock away more than $15,000 per year, do so. Your earliest invested dollars are your most powerful, as they have the most time in which to grow for you. As you advance in your career and earn more, invest more.

Stick to stocks

It's hard to beat the stock market as an effective wealth builder over long periods. You can invest in stocks via low-fee index funds such as the SPDR S&P 500 ETF (SPY), Vanguard Total Stock Market ETF (VTI), and Vanguard Total World Stock ETF (VT). Respectively, they'll spread your dollars across about 80% of the U.S. market, all of the U.S. market, or most of the world's stock market.

Consider aiming to beat the market

If you're willing to learn a lot about investing and can add some carefully chosen individual stocks to your mix, you might achieve a greater-than-average growth rate -- especially if you end up choosing some growth stocks that turn out to be amazing performers. If you do this, consider following The Motley Fool's investing philosophy, which will have you buying 25 or more stocks and aiming to hold on to them for at least five years. And remember that you can build considerable wealth just by sticking with simple index funds, too.

Spend less

To be really aggressive, you'll need to cut back on your spending a lot. There are many possible ways to do so. Some people do everything they can for a few years or more -- such as working a side gig or two, learning to maintain their own home instead of hiring professionals, growing much of their own food, and staying out of debt. Instead of paying for lots of streaming services, they may just subscribe to one, and read a lot of books from their local library. Also, some two-income couples manage to live on just one of their incomes, socking away the other. 

Learn more

For the best results, read more than this article on how to get to a million dollars and beyond. Read some books that offer more ways to spend less, save more, and invest effectively. Even just reading more about index funds may give you more confidence in them, which can help you stick with them. You might also learn more about aggressive strategies such as the Financial Independence, Retire Early (FIRE) program.

So don't think that you can't become a millionaire -- because you may be able to. And even if you fall short, acting on some or all of the smart moves above may at least fatten your nest egg considerably, giving you a more comfortable retirement. Don't leave your retirement up to chance or whatever Social Security delivers.