What you specify is not what TurboTax is using. It is on the order of 50% over that and does not seem to be any reasonable function of other numbers in the return, unless maybe they actually count only capital gains from 1099B and not capital losses, which would require counting each stock transaction on Schedule D that was a gain and ignoring losses, since 1099B only summarizes short and long term, not gain vs loss totals. That seems like the wrong thing to do (so I do not want to go to the trouble of checking for that). Your instructions are not in irs.gov for line 3e. This seems to be a bug in TurboTax, and if it is not, Intuit should add a worksheet to explain where the number comes from.
