Doubling Your Money This calculator demonstrates the power of compound interest. You are viewing this website at a small screen resolution which doesn't support calculators. Click here to view this calculator. Share | Related Content The Power of Compound Interest Learn how to harness the power of compound interest for your investments. Weighing the Benefits of Prepaid Debit Cards It's important to understand the pros and cons when considering a prepaid debit card. Paying Off a Credit Card Enter various payment options and determine how long it may take to pay off a credit card.