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 Retirement Is a Beginning Key questions to answer when you are considering retirement. Who Is Your Trusted Contact? This investment account question is vital and answered as early as possible. Should You Ever Retire? A growing number of Americans are pushing back the age at which they plan to retire. Or deciding not to retire at all.