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 Question Thank you! Oops! Related Content The Average American Budget Learn about the average American budget in this fun and interactive piece. My Retirement Savings Estimate how long your retirement savings may last using various monthly cash flow rates. What Is a Roth 401(k)? Roth 401(k) plans combine features of traditional 401(k) plans with those of a Roth IRA.