By Michelle Skinner, MCU Communications Director

If you’re in your late teens or early 20s, you’ve probably sat through years of math classes. But there’s one equation that could have a bigger impact on your future than anything on a final exam: compound interest.

That’s too bad because compound interest is one of the most powerful tools for building wealth. It’s also the closest thing you’ll ever find to a money-making superpower that doesn’t require a cape or a crystal ball.

What Is Compound Interest?

Compound interest is what happens when your money earns money, and then that money starts earning money, too.

Think of it like a snowball rolling down a hill. It starts small, but as it rolls, it picks up more snow and grows faster and faster.

The key is giving it enough time. Remember, it’s time in the market, not timing the market. You learned that from the personal finance blogs last month, right? Right?! If not, check out our series of personal finance blogs on investing.

The 20-Year-Old vs. The 30-Year-Old

Let’s look at a simple example. Meet Lando and Max. (Can you tell I’m in my Formula 1 Era?) Lando starts investing at age 20. Max waits until age 30.

Both invest $100 per month and earn an average annual return of 7%.

By age 60:

• Lando has contributed $48,000 and ends up with about $262,000.
• Max has contributed $36,000 but ends up with only about $122,000.

Lando invested just $12,000 more over a lifetime, but ended up with more than double the money.

Why? Time.

Not a secret stock tip… Not getting lucky…. Just starting earlier and the power of compound interest at work.

Now, keep in mind that this is an example. All investment portfolios and personal contributions are different and are not guaranteed to perform at 7%. Talk to your favorite financial advisor to make a plan that works for you.

Small Amounts Matter More Than You Think

A lot of young adults assume investing is something rich people do after they’ve bought a house, paid off debt, and figured out life.

Spoiler alert: most people never feel completely “ready” or like an “adult.”

The good news is you don’t need thousands of dollars to get started. Even investing $25 or $50 a month can make a meaningful difference over several decades.

That’s because compound growth isn’t about making huge moves. It’s about making consistent moves over time.

Think of it this way: skipping one fast-food meal a week could add thousands of dollars to your future account balance. That’s a pretty expensive chicken sandwich.

Why Trying to Pick the Perfect Investment Can Backfire (Are we still on the car theme? Maybe.)

If you have a crystal ball and know how to pick the latest and greatest stock buys, let us know. We want to pick your brain about the upcoming football season in addition to the stock market.

Could you find the next big stock? Maybe. (We’re being generous with “maybe” here. What we really want to say is “no,” but there’s always that 01% chance.) But history shows that consistently investing over long periods — when it is building compound interest — is more important than trying to perfectly time the market or find a winning prediction.

Why Credit Unions Are a Smart Place to Start

If you’re beginning your financial journey, choosing the right financial institution matters.

Credit unions are designed to serve their members, not outside shareholders. That means they often focus on helping people build strong financial habits through lower fees, competitive rates, and personalized guidance.

Many credit unions also offer savings accounts, certificates, investment services, financial education resources, and budgeting tools that can help young adults create a solid foundation.

In other words, they’re not just a place to park your money. They’re a partner in helping your money grow.

The Bottom Line

The biggest investing mistake isn’t choosing the wrong stock. It’s waiting until things are lined up “perfectly.”

The difference between starting at 20 and starting at 30 can add up to hundreds of thousands of dollars over your lifetime. Compound interest rewards patience, consistency, and time more than perfection.

So whether you’re investing $25, $50, or $100 a month, the most important step is getting started.

Future you will be very glad you did. And, unlike that impulse purchase you made at 2:00 a.m., this is one financial decision you’re unlikely to regret.

Hint: Automating deposits into your investment fund is a great way to “pay yourself first.” This blog can teach you how to trick yourself into saving more.

Important Disclosure

This article is intended for educational and informational purposes only and should not be considered investment, tax, legal, or financial advice. Investing involves risk, including the possible loss of principal. Every individual’s financial situation, goals, and risk tolerance are different. Before making investment decisions, consider consulting with a qualified financial professional regarding your specific circumstances. Past performance does not guarantee future results.