you can also compare your taxable income (line 15 of the 1040) with and without the 1231 gain. if no other item of income or deduction is being affected then the before and after amount should only increase by the 1231 gain. if it's not then you'll need to look at each line 1-15 to see which one changes. if it's line 8 you'll have to see which line on that schedule changes. If you post the line number (let us know the line number id it's schedule 1) perhaps, we can tell you why. if the line 15's doesn't change that means one of these lines on the 1040 changed
16,17,19,20,23,27-29,31 these would include changes to schedules 2 and 3. we may me able to explain why if you post the line number and if a schedule the line and schedule number.
