What is Compound Interest?

Compound interest is often called the "eighth wonder of the world" because of its ability to grow wealth exponentially. Unlike simple interest, which is only calculated on the initial principal, compound interest is calculated on the principal plus any interest already earned.

Our Compound Interest Calculator helps you visualize this growth, showing you how small, consistent investments can turn into significant wealth over time.

How to Use the Compound Interest Calculator

To get an accurate projection of your investment's future value, enter the following:

• Principal Amount: Your initial starting balance.
• Interest Rate: The expected annual return on your investment.
• Time Period: How long you plan to let the money grow.
• Compounding Frequency: How often interest is added (daily, monthly, annually, etc.).
• Regular Contributions: (Optional) Any additional money you plan to add on a recurring basis.

The Compound Interest Formula

The standard formula for compound interest is:

Where:

• A: The final amount (future value).
• P: The principal amount.
• r: The annual interest rate (decimal).
• n: The number of times interest compounds per year.
• t: The number of years the money is invested.

Compound Interest Calculator FAQs

How does compounding frequency affect my returns?

The more frequently interest is compounded, the faster your money grows. For example, daily compounding will result in a slightly higher final balance than annual compounding, even with the same interest rate.

What is the "Rule of 72"?

The Rule of 72 is a quick way to estimate how long it will take for your money to double. Simply divide 72 by your annual interest rate. For example, at a 6% return, your money will double in approximately 12 years (72 / 6 = 12).

Is compound interest always good?

Compound interest is great for investments, but it can work against you with debt. Credit cards, for example, often compound interest daily, which is why small balances can grow so quickly if not paid off.