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 Tax Freedom Day Assess how many days you'll work to pay your federal tax liability. The Fed and How It Got That Way Here is a quick history of the Federal Reserve and an overview of what it does. Paying Off a Credit Card Enter various payment options and determine how long it may take to pay off a credit card.