What Is Compound Interest and How Does It Work?

Maria Garcia

Maria Garcia

Certified Financial Planner (CFP)

November 26, 2025
5 min read

The Power of Compound Interest: Your Money Making Money

Compound interest is the interest you earn not only on your initial principal but also on the accumulated interest from previous periods. As Investopedia defines it, it is "interest on interest," and it's what makes a sum of money grow at an accelerating rate over time.

How Compound Interest Works: A Simple Example

Imagine you invest $1,000 and it earns 10% interest per year.

  • Year 1: You earn $100 in interest ($1,000 x 10%). Your new balance is $1,100.
  • Year 2: You earn $110 in interest ($1,100 x 10%). Your new balance is $1,210.
  • Year 3: You earn $121 in interest ($1,210 x 10%). Your new balance is $1,331.

Notice how the amount of interest you earn increases each year. That's the magic of compounding. The longer your money stays invested, the more powerful this effect becomes.

The Two Key Ingredients: Time and Rate of Return

  1. Time is Your Greatest Ally: The earlier you start investing, the more time your money has to compound. Someone who starts investing in their 20s can end up with significantly more wealth than someone who starts in their 40s, even if they invest less money overall.
  2. Rate of Return Matters: A higher rate of return will speed up the compounding process. This is why investing in assets with growth potential, like stocks, is a key strategy for long-term wealth building.

See Compounding in Action with Moneko

  • Visualize Your Growth: Use the Moneko Compound Interest Calculator to see how your savings can grow over time with different contribution amounts and interest rates.
  • Plan Your Investments: Chat with our AI Financial Advisor about investment strategies that can help you harness the power of compounding for your retirement goals.
  • Set It and Forget It: Create a recurring investment goal in your Dashboard to make consistent contributions and let compounding do the heavy lifting.

Disclaimer: This content is for informational purposes only and does not constitute financial advice. All investment decisions carry risk. Conduct your own thorough research or consult a qualified financial advisor.

Maria Garcia

Maria Garcia

Maria Garcia is a Certified Financial Planner (CFP) dedicated to helping individuals and families build sustainable wealth. She specializes in retirement planning, emergency savings, and understanding core financial concepts. Maria's approach is to demystify finance and make it approachable for everyone, regardless of their starting point.

Share: