How Compound Interest Works Use this calculator to better see the potential impact of compound interest on an asset. You are viewing this website at a small screen resolution which doesn't support calculators. Click here to view this calculator. Have A Question About This Topic? Name Email Address Message Thank you! Oops! Related Content 18 Years’ Worth of Days The average retirement lasts for 18 years, with many lasting even longer. Will you fill your post-retirement days with purpose? Should You Borrow from Your 401(k)? Does it make sense to borrow from my 401(k) to pay off debt or to make a major purchase? Saving for Retirement This calculator can help you estimate how much you may need to save for retirement.