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? Name Email Address Question Thank you! Oops! Test Your Investment Knowledge! How much do you know about investing? Take our quiz and find out instantly. First Name Last Name Email Address Thank you! Oops! Related Contents The Power of Compound Interest Learn how to harness the power of compound interest for your investments. A Penny Saved is Two Pennies Earned Here are some simple and inexpensive energy-saving tips that may help you save money. Paying Off a Credit Card Enter various payment options and determine how long it may take to pay off a credit card.