Free Compound Interest Calculator 2026 - Calculate Compound Interest & Growth
See the power of compound interest with our free calculator. Calculate how your money grows with different compounding frequencies (monthly, quarterly, or annually).
What is Compound Interest? Complete Guide 2026
What is Compound Interest? Compound interest is interest calculated on the initial principal and accumulated interest from previous periods. This means you earn interest on both your original investment and the interest you've already earned, causing your money to grow exponentially over time.
Simple Interest vs Compound Interest: Simple interest is calculated only on the principal amount, while compound interest is calculated on the principal plus previously earned interest. Compound interest grows your money faster over time, which is why it's called the "eighth wonder of the world" by Albert Einstein.
Compounding Frequency: The frequency of compounding (monthly, quarterly, or annually) affects how much interest you earn. More frequent compounding (monthly vs annually) results in higher returns because interest is calculated and added more often. Our calculator lets you compare different compounding frequencies to see the difference.
The Power of Time: Time is the most important factor in compound interest. The longer your money compounds, the more it grows. Starting early and letting your money compound over decades can result in significant wealth accumulation, even with modest contributions.
Frequently Asked Questions - Compound Interest Calculator
Compound interest is interest calculated on the initial principal and accumulated interest from previous periods. This means you earn interest on both your original investment and the interest you've already earned, causing your money to grow exponentially over time. This is why compound interest is often called the "eighth wonder of the world."
Simple interest is calculated only on the principal amount, while compound interest is calculated on the principal plus previously earned interest. Compound interest grows your money faster over time. For example, with simple interest, $1,000 at 10% for 10 years becomes $2,000. With compound interest, it becomes $2,594.
More frequent compounding (monthly vs quarterly vs annually) results in higher returns because interest is calculated and added more often. For example, $10,000 at 8% for 10 years: annually = $21,589, quarterly = $22,080, monthly = $22,196. The difference may seem small, but it compounds over longer periods.
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