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 Question Thank you! Oops! Related Content Estimating the Cost of College This worksheet can help you estimate the costs of a four-year college program. Qualifying For Medicare Under Age 65 You might qualify for Medicare if you’re under 65-years-old. This article will explain the conditions where you may qualify for Medicare early. What Do Your Taxes Pay For? Here's a breakdown of how the federal government spends your tax money.