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. Have A Question About This Topic? Name Email Address Message Thank you! Oops! Related Content Inflation & Retirement Estimate how much income may be needed at retirement to maintain your standard of living. Preparation is the Key to Retirement The simplest ideas can sometimes make a massive difference over time. Enjoy this brief video to learn more. 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.