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 Making Your Tax Bracket Work Have you explored all your options when it comes to managing your taxable income? You May Need to Make Estimated Tax Payments If… Have income that isn’t subject to tax withholding? Or insufficient withholdings? You may have to pay estimated taxes. Comparing Investments This calculator compares the net gain of a taxable investment versus a tax-favored one.