Should I Pay Off Debt or Invest? This calculator will help determine whether you should invest funds or pay down debt. 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 Question Thank you! Oops! Related Content Comparing Investments This calculator compares the net gain of a taxable investment versus a tax-favored one. 16 Wall Street Cliches in 60 Seconds Pundits say a lot of things about the markets. Let's see if you can keep up. The Anatomy of an Index The S&P 500 represents a large portion of the value of the U.S. equity market, it may be worth understanding.