You can open the 1040 and right-click on the amount in 11a and 11 to see the source of the amount. Capital gains tax is not simply excluded, rather, if you have capital gains, the tax calculation is done on a different worksheet, such as the capital gains worksheet, or the Qualified Dividends and Capital Gains worksheet. You can actually click on and open to see the tax calculation on the worksheet. Click on the Forms icon on the upper right, then click on the 1040 on the left.