Capital Gains Tax Estimator Use this calculator to estimate your capital gains tax. You are viewing this website at a small screen resolution which doesn't support calculators. Click here to view this calculator. Share | Related Content Social Security Taxes Estimate how much of your Social Security benefit may be considered taxable. What Is a 1035 Exchange? 1035 exchanges provide a way to trade-in an annuity contract or life insurance policy without triggering a tax liability. Federal Income Tax Use this calculator to estimate your income tax liability along with average and marginal tax rates.