Tax Reform: Before and After Full Size Version Share | Have A Question About This Topic? Name Email Address Message Thank you! Oops! Related Contents The Facts About Income Tax Millions faithfully file their 1040 forms each April. But some things about federal income taxes may surprise you. Understanding Marginal Income Tax Brackets An inside look at how marginal income tax brackets work. Federal Income Tax Use this calculator to estimate your income tax liability along with average and marginal tax rates.