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 | Have A Question About This Topic? Address Thank you! Oops! Related Contents Federal Income Tax Use this calculator to estimate your income tax liability along with average and marginal tax rates. Does Your Child Need to File an Income Tax Return? When your child has income, there’s a good chance that he or she will need to report it and pay taxes. Comparing Investments This calculator compares the net gain of a taxable investment versus a tax-favored one.