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 Latte Lie and Other Myths Do you know these three personal finance sayings? U.S. Personal Savings Rate What can be learned from the savings rate? What Is My Current Cash Flow? Assess whether you are running “in the black” or “in the red” each month.