The Facts About Income Tax Millions faithfully file their 1040 forms each April. But some things about federal income taxes may surprise you. Share | Related Content Home Mortgage Deduction Use this calculator to assess the potential benefits of a home mortgage deduction. Tax Reform: Before and After What did the 2017 Tax Cuts and Jobs Act change? Here's a quick snapshot. Capital Gains Tax Estimator Use this calculator to estimate your capital gains tax.