Comparing Investments This calculator compares the net gain of a taxable investment versus a tax-favored one. 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? The Economic Journey of Your Morning Coffee Few contemplate the complex journey that brought their coffee from farm to kitchen table. Choosing a Retirement Plan that Fits Your Business To choose a plan, it’s important to ask yourself four key questions.