Compound Interest Calculator | Growth with Contributions
Calculate future value, total principal, and compound interest from initial balance, monthly contribution, annual rate, and years.
Future Value
$0.00
Total Principal Added
$0.00
Estimated Interest Earned
$0.00
Calculate Compound Interest Growth
Enter initial balance, monthly contribution, annual interest rate, and years to estimate future value, principal added, and compound interest earned.
Contributions and Time Drive Compounding
Small regular contributions can grow significantly over long periods, but real returns may vary with fees, taxes, inflation, and market conditions.
About This Tool
Compound Interest Calculator shows how an investment or savings balance grows over time when interest is earned on both the principal and previously accumulated interest. It illustrates the long-term power of reinvesting returns.
When to Use It
Use this when planning long-term savings to see how a regular contribution grows, when comparing different interest rates and compounding frequencies, or when setting a savings goal timeline.
How to Use
- Enter the initial principal amount.
- Enter the annual interest rate.
- Set the compounding frequency: monthly, quarterly, or annually.
- Enter the investment period in years.
- Click Calculate to see the final balance and total interest earned.
Frequently Asked Questions
What is the difference between simple and compound interest?
Simple interest is calculated only on the original principal. Compound interest is calculated on the principal plus accumulated interest, causing the balance to grow faster over time.
How does compounding frequency affect growth?
More frequent compounding produces slightly higher returns. Monthly compounding grows faster than annual compounding at the same nominal rate.
What is the rule of 72?
Divide 72 by the annual interest rate to estimate how many years it takes to double your money. At 6 percent per year, money doubles in approximately 12 years.