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? Name Email Address Question Thank you! Oops! Related Contents Tax Freedom Day Assess how many days you'll work to pay your federal tax liability. Tax Reform: Before and After What did the 2017 Tax Cuts and Jobs Act change? Here's a quick snapshot. Federal Income Tax Use this calculator to estimate your income tax liability along with average and marginal tax rates.