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 Facts About Income Tax Millions faithfully file their 1040 forms each April. But some things about federal income taxes may surprise you. IRA Withdrawals that Escape the 10% Tax Penalty The list of IRA withdrawals that may be taken without incurring a 10% early penalty has grown. How Solid is Your Offensive Line? As quarterback of your life, here’s a fun way to think about protecting your financial future.