Zach points out that the less you save, the more crucial it is to invest. “By saving just $2,000 per year with five percent returns, it will take you 66 years to become a millionaire,” he writes. “But by saving that same amount with 10 percent returns, you can become a millionaire in only 41 years.”

The stock market is volatile and it’s never possible to guarantee a 10 percent return rate, but the differences he cites do speak to the power of compound interest and the importance of investing generally.

The chart also doesn’t account for the many variables that can affect your wealth over several decades, including windfalls, emergencies and rises or dips in the market. But if you’re aiming to retire with $1 million or more in the bank, it can give you a good idea as to how close you are to reaching your goals.

Ready to put your money to work? The simplest starting point is to invest in your employer’s 401(k) plan, a tax-advantaged retirement savings account. Next, consider alternate retirement savings accounts as well, such as a Roth IRA, traditional IRA and/or a health savings account.

You can also research low-cost index funds, which Warren Buffett recommends, and online investment platforms known as robo-advisers.

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