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Guide · Investing basics

Simple Interest vs Compound Interest: Clear Examples (2025 Guide)

Interest can grow your money — but depending on the method, the results can be very different. This guide explains simple interest vs compound interest with real USD examples so you can instantly see the difference.

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Simple Interest: The Basics

Simple interest grows in a straight line. You earn interest only on the original principal.

Simple Interest Formula

Interest = Principal × Rate × Time

Example: $10,000 at 5% for 5 years

  • Interest each year: $500
  • Total interest after 5 years: $2,500
  • Final value: $12,500

No acceleration — earnings stay the same every year.


Compound Interest: The Basics

Compound interest grows your money exponentially.
You earn interest on the principal and on the interest you already earned.

Compound Interest Formula

A = P (1 + r/n)(n·t)

Example: $10,000 at 5% for 5 years, compounded annually

  • Year 1: $10,500
  • Year 2: $11,025
  • Year 3: $11,576
  • Year 4: $12,155
  • Year 5: $12,763

Total interest earned: $2,763
(That’s $263 more than simple interest — with the same rate and time.)


Simple vs Compound Interest: Side-by-Side Comparison

Feature Simple Interest Compound Interest
Interest earned on past interest? No Yes
Growth pattern Linear Exponential
Best for Short-term loans Savings & long-term investing
Typical total returns Lower Higher

Which One Helps Your Money Grow More?

If you're comparing growth over several years, compound interest almost always wins. The longer the time period, the bigger the gap becomes — often dramatically.

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Key Takeaways

  • Simple interest grows at a fixed rate — no compounding.
  • Compound interest grows faster because interest earns more interest.
  • Even small differences in rates or years can lead to large differences in outcomes.
  • For savings and investing, compound interest is typically far more powerful.

Next steps

👉 Compare compound growth using the compound interest calculator
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