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 | Have A Question About This Topic? Address Thank you! Oops! Related Contents Saving for College 101 Here’s a crash course on saving for college. The Lowdown on Those Free Credit Scores What’s the deal with your yearly free credit report? Paying Off a Credit Card Enter various payment options and determine how long it may take to pay off a credit card.