And actually on a AGI of 31,400 you would owe $3,539. See IRS Tax Table
https://www.irs.gov/pub/irs-pdf/i1040tt.pdf
But you have capital gains which are taxed at a lower rate. Even though the full amount shows up in the total income on the 1040 line 7, if you have capital gains or qualified dividends the tax is not taken from the tax table but is calculated separately from Schedule D. The tax will be calculated on the Qualified Dividends and Capital Gain Tax Worksheet. It does not get filed with your return. In the online version you need to save your return as a pdf file and include all the worksheets to see it.
