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 Social Security Taxes Estimate how much of your Social Security benefit may be considered taxable. Red Flags for Tax Auditors Here are six flags that may make your tax return prime for an IRS audit. Tax Management Strategies Learn more about taxes, tax-favored investing, and tax strategies.