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 Important Birthdays Over 50 Here's a look at several birthdays and “half-birthdays” that have implications regarding your retirement income. Retirement Redefined Around the country, attitudes about retirement are shifting. How to Make the Tax Code Work for You When you take the time to learn more about how it works, you may be able to put the tax code to work for you.