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 Social Security Taxes Estimate how much of your Social Security benefit may be considered taxable. What You Need to Know About Social Security Every so often, you’ll hear about Social Security benefits running out. But is there truth to the fears, or is it all hype? When Should You Take Social Security Monthly Social Security payments differ substantially depending on when you start receiving benefits.