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 Assess Your Life Insurance Needs This calculator estimates how much life insurance you would need to meet your family's needs if you were to die prematurely. Bull & Bear Markets: A Timeline This helpful infographic will define bull and bear markets, as well as give a historical overview. The Facts About Income Tax Millions faithfully file their 1040 forms each April. But some things about federal income taxes may surprise you.