Einstein once said, “Compound interest is the eighth wonder of the world. He who understands it, earns it … he who doesn’t … pays it.” Understanding the basics of this powerful mathematical tool can ...

Simple interest calculates earnings or payments based solely on the initial principal, while compound interest grows by calculating interest on both the principal and the accumulated interest over ...

On the surface, an interest rate is just a number. How that number applies to debt or equity opens up a world of possibilities. The first consideration is always whether it’s simple interest vs.

Compound interest can help turbocharge your savings and investments, or it can quickly lead to an unruly balance, keeping you stuck in a cycle of debt. Its magic can help you earn more — or owe more.

Einstein allegedly called compound interest the eighth wonder of the world. Benjamin Franklin defined it more poetically: ...

Daniel Jassy, CFA, is an Investopedia Academy instructor and the founder of SPYderCRusher Research. He contributes to Excel and Algorithmic Trading. Compound interest is interest that's calculated on ...

Editor's Note: APYs listed in this article are up-to-date as of the time of publication. They may fluctuate (up or down) as the Fed rate changes. Select will update as changes are made public. Some ...