Compound Interest Calculator

This calculator calculates the interest earned/owed for a statement period, rounded down.

Enter your APR, the daily balance, the compounding period, and the number of days in the statement period.

Compound interest has been called the eighth wonder of the world by Albert Einstein (source). Compound interest is the concept of earning "interest on interest". For example, if you have $100.00 that earns 10% annually, then the first year you earn $10.00 on your initial deposit. However, if you leave you're money in the account instead of withdrawing it, the second year your balance would be $110.00, so you would earn $11.00 in interest. And every year, you're interest would continue to grow.

Warren Buffet, also known as the "Oracle of Omaha", has earned a lot of his wealth due to the concept of compound interest. In fact, most of his wealth has been earned since he turned 50. You can see a great chart from MarketWatch in the article here. Warren Buffet has built a lot of weatlh over time by buying under valued businesses and reinvesting all the dividends and earnings back into the business.