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 Message Thank you! Oops! Want to be Smarter With Your Money? Join our mailing list and get news and info to support your financial goals. First Name Last Name Email Address Thank you! Oops! Related Content What Our Kids Can Teach us About Saving Money Would you guess that Millennials are effectively saving for retirement? Well, they are. Life and Death of a Twenty Dollar Bill How long does a $20 bill last? Paying Off a Credit Card Enter various payment options and determine how long it may take to pay off a credit card.