Money

Here’s how much you need to save each month to be a millionaire in 40 years

The 148th Belmont Stakes
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A record number of Americans are becoming millionaires. As of 2016, there were 10.8 million millionaires nationwide, according to a 2017 report from Spectrem Group. Could you become one of them?

Reaching that milestone isn't the challenge it once was, after all. If you're at the beginning of your career, you still have decades left to save. And even if you're in your 30s or 40s, you may already be on track to reach seven figures by age 67.

CNBC Make It calculated how much you'd have to save each month to become a millionaire in 40 years. Here's how much you'll need to put away, depending on the amount you already have invested.

To become a millionaire in 40 years with no prior savings:

With a 4 percent rate of return: $876.96 per month
With a 6 percent rate of return: $538.46 per month
With an 8 percent rate of return: $321.68 per month

To become a millionaire in 40 years with $5,000 in savings:

With a 4 percent rate of return: $855.91 per month
With a 6 percent rate of return: $510.77 per month
With an 8 percent rate of return: $286.74 per month

To become a millionaire in 40 years with $10,000 in savings:

With a 4 percent rate of return: $834.86 per month
With a 6 percent rate of return: $483.08 per month
With an 8 percent rate of return: $251.80 per month

The average annualized total return for the S&P 500 index is more than 9 percent. But it's important to keep in mind that these calculations don't account for the many variables that can affect wealth over several decades, including windfalls, emergencies and rises or dips in the market.

Of course, saving hundreds or thousands a month is an ambitious goal, and more than most Americans can manage. But getting into the habit of saving any amount will be great for you in the long run.

Here are a few simple, low-stress ways to start investing:

  • Sign up for your employer's 401(k) plan and take full advantage of any company match, which essentially gives you free money
  • Contribute to a Roth IRA or traditional IRA, an individual retirement account that offers tax breaks
  • Use micro-investing apps such as Acorns, which help you begin by investing small amounts of what it calls your "spare change." The app rounds up your purchases to the nearest dollar and automatically puts your coins to work
  • Try other apps that aim to make investing simple
  • Consider automated investing services known as robo-advisors that can help you out no matter how much you have in the bank
  • Research low-cost index funds, which Warren Buffett recommends

Don't miss: I just invested my first $7,000 at age 26—here's where I decided to put it

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