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. Share | Have A Question About This Topic? Name Email Address Message Thank you! Oops! Related Content A Fruitful Retirement: Social Security Benefit Taking your Social Security benefits at the right time may help maximize your benefit. 18 Years’ Worth of Days The average retirement lasts for 18 years, with many lasting even longer. Will you fill your post-retirement days with purpose? From Boats to Brokers From the Dutch East India Company to Wall Street, the stock market has a long and storied history.