The Power of Compound Interest

Why it really pays to invest early in a retirement account
Money in a savings or retirement account grows over time as it earns interest. But the interest rate isn’t the only factor that determines how much it grows; compounding interest helps your funds grow faster because it lets you earn interest on the money you deposit plus previously earned interest.

Compounding interest gives young investors great power to save for retirement, even if they don’t currently have much to save.

People in their 20s and 30s who are working to build their careers are often tempted to put off investing in retirement for a time when they are more established financially. By doing so, however, they miss out on the big advantage they have over older, wealthier savers: time.

“If you invested $10,000 in a mutual fund and the fund earned a 7% return for the year, you’d gain $700,” according to NerdWallet. “Over the years, that money can really add up: If you kept that money in a retirement account over 30 years and earned that average 7% return, for example, your $10,000 would grow to more than $76,000.”

To test out the power of compound interest for yourself, try the Compound Interest Calculator from NerdWallet. It can show you exactly how far your money could go if you started saving today. Just plug in hypothetical savings amounts at https://www.nerdwallet.com/banking/calculator/compound-interest-calculator.

The earlier you start investing, the more time your money has to compound, and when you do the calculations, it becomes clear that saving a little bit of each paycheck today can add up to a much bigger sum at age 65 than if you wait a few decades to start saving, even if you can afford to save more each month when you’re older. The bottom line is that to truly take advantage of the power of compound interest, you need to start saving as early as possible, and the advantage you gain by doing so cannot be overstated.

Business Insider calculated how much you would need to save each month to reach $1 million by age 65 at a 6 percent return rate, and the results are astounding. If you start saving at age 20, you only need to invest $361.04 each month, while starting at age 30makes the required monthly savings nearly double to $698.41. If you wait until you are 50, you need to put away $3,421.46 each month to end up with the same amount at age 65.

You can see a chart that illustrates the calculated monthly savings required for each age group at http://www.businessinsider.com/compound-interest-monthly-investment-2014-3/#.U6xcEI1dWVh.

“When you start saving outweighs how much you save,” says Business Insider contributor Libby Kane. “Retirement accounts such as 401(k)s and Roth IRAs aren’t just savings accounts-they’re actively invested, and therefore have the potential to make the most of this benefit.”

If you’ve been inspired by the mathematical magic of compound interest, harness that motivation by talking to your financial institution about opening up a retirement account or by committing to making regular contributions to your existing savings and retirement accounts.