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 Avoiding Cognitive Decline Try these activities to keep your brain sharp. Choosing a Retirement Plan that Fits Your Business To choose a plan, it’s important to ask yourself four key questions. How Income Taxes Work A quick look at how federal income taxes work.