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 | Related Content The Financial Literacy Crisis Many Americans are operating their personal finances with only the barest minimum of knowledge. How Income Taxes Work A quick look at how federal income taxes work. Defining Your Priorities Achieving a long-term goal, like retirement, starts by taking small actions today.