What is line 11a and 12 a for on the 1040 form? how do they come up with that number?

[BMcCalpin]

This is confusing because the IRS in redesigning the 1040 moved a fair number of lines to other schedules, in this case, Schedules 2 and 3.

So now, the 1040 form has to ask you for the calculated tax on line 11a and then adds to this the other taxes on Schedule 2 to make line 11.

Ditto with line 12a: the original Child Tax Credit is on line 12a, and all the other credits are imported from Schedule 3.

In detail:

Here are the IRS instructions on what goes into line 11a:
• Tax on your taxable income. Figure the tax using one of the methods described, later.
• Tax from Form(s) 8814 (relating to the election to report child's interest or dividends). Check the appropriate box.
• Tax from Form 4972 (relating to lump-sum distributions). Check the appropriate box.
• Tax due to making a section 962 election (the election made by a domestic shareholder of a controlled foreign corporation to be taxed at corporate rates). See section 962 for details. Check box 3 and enter the amount and “962” in the space next to that box. Attach a statement showing how you figured the tax.
• Recapture of an education credit. You may owe this tax if you claimed an education credit in an earlier year, and either tax-free educational assistance or a refund of qualified expenses was received in 2018 for the student. See Form 8863 for more details. Check box 3 and enter the amount and “ECR” in the space next to that box.
• Any tax from Form 8621, line 16e, relating to a section 1291 fund. Check box 3 and enter the amount of the tax and “1291TAX” in the space next to that box.
• Repayment of any excess advance payments of the health coverage tax credit from Form 8885. Check box 3 and enter the amount of the repayment and “HCTC” in the space next to that box.
• Net tax liability deferred under section 965(i). If you have a deferred net 965 tax liability under section 965(i), check box 3 and enter (as a negative number) the amount of the deferred net 965 tax liability and “965” on the line next to that box.
• Triggering event under section 965(i). If you had a triggering event under section 965(i) during the year and did not enter into a transfer agreement, check box 3 and enter the amount of the triggered deferred net 965 tax liability and enter “965INC” on the line next to the box.

Note that line 11 is the sum of 11a plus any amount from Schedule 2 (Form 1040).

Line 12a is from the 2018 Child Tax Credit and Credit for Other Dependents Worksheet in the 1040 Instructions. It is what you would think of as the credit.

Line 12 is the sum of line 12a and any non-refundable credits from Schedule 3.

[CCottonAllen]

This still doesn’t say how line 11a is calculated 

[VolvoGirl]

Line 11a on what form and what year?  Starting in 2018 the line numbers all changed around.

[scotsilvers]

You told us the same thing the instructions say in the tax booklet 

[Irene2805]

Line 11a is the sum of line 9 (your standard or itemized deductions) and line 10 (the Qualified Business Deduction).  

If  you are using the CD/Download version of TurboTax, you can see where the figures come from in Forms Mode.

1. Go into Forms Mode by clicking on the Forms icon in the top right of the blue bar. 
2. In the Forms in My Return list on the left, click the form you want to review.  The form will appear on the right side of the screen.
3. You can view the form on the screen or you can print a copy by clicking the Print box at the bottom of the screen. 
4. To see where the figure comes from, click on the field and then click on the magnifying glass.
5. To return to the interview, click on the Step-By-Step icon in the top right of the blue bar.  

Line 12a is the tax calculated on your taxable income (line 11b).  

The IRS specifies the method of calculating the tax, depending on the type of income shown in your return.

To see the method used to calculate your taxes, go to the Federal 1040 and look at the Tax Smart Worksheet.   To view the Tax Smart Worksheet, please follow these steps:

TurboTax Online

1. While in your return, click Tax Tools > Tools  (in the black bar at the left of the screen).  
2. Under "Other helpful links" click on View Tax Summary.
3. Click on the Preview my 1040 link in the black bar.
4. Using the scroll bar at the side of the 1040 window, scroll to the Tax Smart Worksheet between lines 11 and 12. 
5. Line A will contain the amount of tax calculated, along with an X indicating the method used to calculated your tax.  
6. To go back to your return, click on the Back link in the black bar.

TurboTax Desktop

1. Go into Forms Mode by clicking on the Forms icon in the top right of the blue bar at the top of your screen.  
2. In the Forms in My Return list, click on 1040/1040SR Wks. 
3. Using the scroll bar at the side of the 1040 window, scroll to the Tax Smart Worksheet on page 3.
4. Line A will contain the amount of tax calculated, along with an X indicating the method used to calculated your tax.  To view the worksheet, right-click on the number in line A and select Data Source from the menu that pops up.  

[JJK2]

Line 12a on IRS form 1040 has checkboxes to indicate the source of the tax calculation. The 3rd box has a blank beside it. If I'm filling out this form on paper by hand to mail to the IRS, assuming neither box 1 nor 2 applies, I'd check box 3 and put some reference to the calculation source on the blank. (In our case, it's the Qual Div/Cap Gn worksheet, but it could be any of several sources.)

Think TurboTax should do the same.  What else would this box/space be for?

If Intuit reads these, please consider this a Request for Improvement (RFI), if not a bug report.