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 The Facts About Income Tax Millions faithfully file their 1040 forms each April. But some things about federal income taxes may surprise you. IRA Withdrawals that Escape the 10% Tax Penalty The list of IRA withdrawals that may be taken without incurring a 10% early penalty has grown. When Heirs are Imperfect The money problems or bad lifestyle habits of adult children could lead to the squandering of any inheritance they receive.