Federal Income Tax Use this calculator to estimate your income tax liability along with average and marginal tax rates. 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 Protecting Your Business from the Loss of a Key Person Business owners may be able to protect themselves from the financial consequences of losing a key employee. Choosing a Retirement Plan that Fits Your Business To choose a plan, it’s important to ask yourself four key questions. What If You Get Audited? The chances of an IRS audit aren't that high. And being audited does not necessarily imply that the IRS suspects wrongdoing.