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 My Retirement Savings Estimate how long your retirement savings may last using various monthly cash flow rates. Inflation & Retirement Estimate how much income may be needed at retirement to maintain your standard of living. Tax Deductions You Won't Believe Here are some examples of deductions from the IRS that were permitted and some that were, uh, too creative.