Compound Interest Tools
Compound interest is the snowball effect of money. Our compound interest tools help you project the growth of your investments, savings, or retirement accounts over decades by factoring in regular contributions and varying interest rates.
Calculators
Our free online compound interest tools to help you calculate and plan.
Related Guides
Learn more with our comprehensive guides and articles.
What is Compound Interest? Guide to Compounding Growth
Compound interest is the interest you earn on both your original money and on the interest you keep accumulating. It is the core concept behind long-term wealth building.
Simple vs Compound Interest: What is the Difference?
A detailed breakdown of simple versus compound interest. Learn the math behind each and understand how compounding frequency affects your money.
Glossary Terms
Key definitions you should know.
Worked Examples
Step-by-step examples showing exactly how the math works.
Investing $500 a Month for 30 Years
This example demonstrates the power of compound interest over a long time horizon. Even though the investor only put in $180,000 of their own money, the balance grew to over $600,000 because the interest earned kept generating its own interest.
View in Calculator →Frequently Asked Questions
What is compound interest?
Compound interest is interest calculated on the initial principal, which also includes all of the accumulated interest from previous periods.