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 Capital Gains Tax Estimator Use this calculator to estimate your capital gains tax. How to Appeal Your Property Taxes For homeowners who think their property taxes are too high, there are ways to appeal. Comparing Investments This calculator compares the net gain of a taxable investment versus a tax-favored one.