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 Eight Mistakes That Can Upend Your Retirement There are common mistakes you can avoid when saving for retirement. Good Health is Good Business Good employee health can be great for the company’s bottom line. The Facts About Income Tax Millions faithfully file their 1040 forms each April. But some things about federal income taxes may surprise you.