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 Comparing Investments This calculator compares the net gain of a taxable investment versus a tax-favored one. Tax Rules When Selling Your Home The tax rules governing profits you realize from the sale of your home have changed in recent years. Home Mortgage Deduction Use this calculator to assess the potential benefits of a home mortgage deduction.