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 Message Thank you! Oops! Related Content Making Your Tax Bracket Work Have you explored all your options when it comes to managing your taxable income? Red Flags for Tax Auditors Here are six flags that may make your tax return prime for an IRS audit. Tax Freedom Day Assess how many days you'll work to pay your federal tax liability.