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! Related Content The Power of Compound Interest Learn how to harness the power of compound interest for your investments. Life and Death of a Twenty Dollar Bill How long does a $20 bill last? Historical Inflation This calculator shows how inflation over the years has impacted purchasing power.