Here's the No. 1 factor that helped 37% of American workers feel good about their retirement savings.

The best way to secure your retirement savings, according to Americans, is to invest early.

According to CNBC's August 2024 Your Money retirement survey conducted with SurveyMonkey, only 37% of non-retired Americans are either "on schedule" or "ahead of schedule" with their retirement investments.

Although more than half of Americans admit to being behind on their retirement savings, those who feel confident about their savings say that early contributions are the top factor in accumulating wealth for retirement.

The survey found that low debt, homeownership wealth, good saving habits, employer-sponsored retirement accounts, and earning good income were the most important factors for financial stability, along with other less-cited reasons. Respondents were asked to select all applicable reasons.

Investing early is highly beneficial, and developing the habit while young is crucial.

The power of compound interest

A recent study by Morningstar revealed that 79% of Americans with at least 20 years of future participation in an employer-sponsored retirement plan, such as a 401(k), will have sufficient savings to sustain them throughout retirement.

Early contributions to retirement accounts can significantly improve one's financial position, as they typically represent a substantial portion of an individual's wealth.

One reason these investment accounts are so powerful is due to compound interest, which allows interest to be earned on both the initial principal amount and any accumulated interest, resulting in exponential growth over time.

Marcus Holzberg, a certified financial planner in California, claims that the key to success in the stock market is a well-kept secret.

DON'T MISS: How to master your money and grow your wealth

Using a 25-year-old who contributes $100 monthly to a retirement account that compounds monthly and earns a 5% rate of return as an example, Holzberg estimates that by age 65, the total would be approximately $152,000.

If they started investing at 25, the total would be around $120,000. However, if they waited until 35, the total would shrink to about $83,000. Waiting until 40 reduces the amount further, to around $60,000 — nearly a third of the value compared with starting at 25.

Compounding credit card interest can lead to a rapid increase in unpaid debt balances, which may contribute to the reason why U.S. workers are not saving enough for retirement.

How to get into the habit of investing while you're young

Younger individuals may not have much space in their budgets for retirement contributions due to their lower incomes early in their careers, according to Holzberg.

Robin Giles, a CFP in Texas, emphasizes that the most crucial aspect is to begin investing, regardless of the amount, and to remain consistent. Later, you can always enhance your contributions as your financial situation improves.

"Just like building a muscle, investing requires consistent use to grow, and with time, your money will start working for you through the power of compound interest, ultimately reducing your need for financial work."

Sign up for CNBC's online course to master your money this fall. Our practical strategies will help you hack your budget, reduce your debt, and grow your wealth. Start today to feel more confident and successful. Use code EARLYBIRD for a 30% introductory discount, extended through September 30, 2024, for the back-to-school season.

Sign up for CNBC Make It's newsletter to receive expert advice on work, money, and life.