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 Saving for College This calculator can help you estimate how much you should be saving for college. Saving for Retirement This calculator can help you estimate how much you may need to save for retirement. When Should You Take Social Security Monthly Social Security payments differ substantially depending on when you start receiving benefits.