FINANCIAL KNOWLEDGE

What Is Compound Interest?

Understanding the difference between simple and compound interest is the key to smarter financial planning.

Compound Interest vs Simple Interest comparison chart

The Power of "Interest on Interest"

Compound interest is interest calculated on both the initial principal and all previously accumulated interest. Unlike simple interest, which only earns returns on your original deposit, compound interest allows your money to grow exponentially over time.

This is why Albert Einstein reportedly called it the "eighth wonder of the world." The longer your money compounds, the faster it grows — making early and consistent investing incredibly powerful.

Compound Interest Formula
A = P(1 + r/n)nt
P = Principal · r = Annual rate · n = Compounding frequency · t = Time in years
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Simple Interest

Simple interest is calculated only on the original principal. The interest earned each period remains constant regardless of how long you invest.

Example
$10,000 at 5% for 10 years → $15,000 total
(Earned: $5,000 in interest)
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Compound Interest

Compound interest is calculated on both principal and accumulated interest. Your earnings accelerate over time as interest earns its own interest.

Example (Monthly Compounding)
$10,000 at 5% for 10 years → $16,470 total
(Earned: $6,470 in interest — 29.4% more!)

Key Factors That Affect Compound Interest

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Principal Amount
The larger your starting amount, the more interest you earn
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Time Period
Longer investment horizons lead to exponential growth
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Interest Rate
Even small rate differences matter significantly over time
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Compounding Frequency
More frequent compounding (daily vs yearly) increases returns