Form 1040 Line 16: Tax and How It Is Figured (2025 Return)

Updated October 17, 2026. Quick answer: Line 16 is the tax on your taxable income from line 15, plus a few other taxes that the instructions list. You figure it with the Tax Table, the Tax Computation Worksheet, or one of the other worksheets the instructions name, depending on your situation. Three check boxes next to the line show whether part of the amount came from Form 8814, Form 4972, or another listed item.

Retirement forms read line by line: Form 4972, Form 4972 Part II and Form 4972 lines 18 to 30.

Business use of your home (Form 8829), the saver’s credit (Form 8880), clean vehicle credits (Form 8936) and amended returns (Form 1040-X), read line by line: Form 8936 line 13, Form 8936 line 18 and Form 1040-X lines 6 to 11.

IRS worksheets from the 2025 Form 1040 instructions, read line by line: Tax Computation Worksheet, Foreign Earned Income Tax Worksheet and Form 1040 worksheets.

Schedule D and Schedule E (Form 1040) for 2025, read line by line: Schedule D line 18, Schedule D line 20 and Schedule D lines 21 and 22.

Schedule 3 (Form 1040) for 2025, read line by line: Schedule 3 line 1, Schedule 3 lines 6f to 6k and Schedule 3 lines 6l, 6m and 6z.

What line 16 asks for

The form’s caption reads “Tax (see instructions).” “Check if any from Form(s)”, followed by three boxes. The instructions describe what the entry space holds: “Include in the total on the entry space on line 16 all of the following taxes that apply.” The first item on their list is the main one: “Tax on your taxable income. Figure the tax using one of the methods described later.” Taxable income is line 15, covered on lines 14 and 15. The rest of the return is mapped in Form 1040 line by line.

The check boxes 1, 2 and 3

Box 1 is for Form 8814: “Tax from Form(s) 8814 (relating to the election to report child’s interest or dividends). Check the appropriate box.” Form 8814 has its own page at the Form 8814 page.

Box 2 is for Form 4972: “Tax from Form 4972 (relating to lump-sum distributions).” “Check the appropriate box.”

Box 3 is a catch-all for other listed items. One of them is described this way: “Check box 3 and enter the amount and” a short code in the space next to the box, with the instruction to “Attach a statement showing how you figured the tax.” The instructions list several such items; for each one, read the line 16 instructions or the form they name.

Choosing how to figure the tax

The instructions start with a choice. They ask “Do you want the IRS to figure the tax on your taxable income for you?” The yes answer points to “See chapter 13 of Pub. 17 for details, including who is eligible and what to do.” Otherwise you use one of the methods described next.

The default method is the table: “If your taxable income is less than $100,000, you must use the Tax Table, later in these instructions, to figure your tax.” The instructions add “Be sure you use the correct column.” For larger amounts: “If your taxable income is $100,000 or more, use the Tax Computation Worksheet right after the Tax Table.” This page does not reproduce any table or rate schedule. Read the amount for your own taxable income from the instructions, and see the 2025 tax brackets page for background on the brackets.

When to use a different worksheet

The instructions then say the table and computation worksheet are not used in some cases. A child with investment income may need another form: “Form 8615 must generally be used to figure the tax on your unearned income over $2,700 if you are under age 18, and in certain situations if you are older.”

For capital gains: “Use the Schedule D Tax Worksheet in the Instructions for Schedule D to figure the amount to enter on Form 1040 or 1040-SR, line 16, if:” “You have to file Schedule D, line 18 or 19 of Schedule D is more than zero, and lines 15 and 16 of Schedule D are gains; or” The other trigger is “You have to file Form 4952 and you have an amount on line 4g, even if you don’t need to file Schedule D.”

For qualified dividends and capital gains the instructions say “Use the Qualified Dividends and Capital Gain Tax Worksheet, later, to figure your tax if you don’t have to use the Schedule D Tax Worksheet and if any of the following applies.” The cases listed are “You reported qualified dividends on Form 1040 or 1040-SR, line 3a.” “You don’t have to file Schedule D and you reported capital gain distributions on Form 1040 or 1040-SR, line 7a.” and “You are filing Schedule D, and Schedule D, lines 15 and 16, are both more than zero.” Those lines are explained on the lines 3a and 3b page and the line 7 page. There is a dedicated page for the worksheet at the qualified dividends and capital gain tax worksheet page, and a calculator at the capital gains tax calculator.

Two more methods are named. For farming or fishing income: “If you had income from farming or fishing, your tax may be less if you choose to figure it using income averaging on Schedule J.” For foreign income: “If you claimed the foreign earned income exclusion, housing exclusion, or housing deduction on Form 2555, you must figure your tax using the Foreign Earned Income Tax Worksheet.”

Where the number comes from

The line 16 amount is the result of whichever method applies, not a figure printed on a statement. The Qualified Dividends and Capital Gain Tax Worksheet, for instance, ends with “Enter the smaller of line 23 or line 24. Also include this amount on the entry space on Form 1040 or 1040-SR, line 16.” That worksheet begins with “Before completing this worksheet, complete Form 1040 or 1040-SR through line 15.” So line 15 must be finished first, and the other listed taxes are added to the entry space after the method’s result.

Where it goes next

Line 16 is added to line 17. The form’s captions read “Amount from Schedule 2, line 3” for line 17 and “Add lines 16 and 17” for line 18. Line 18 then continues through the credits to the total. The caption for line 24 reads “Add lines 22 and 23. This is your total tax”. Line 23 is the other taxes line, including self-employment tax, from Schedule 2, line 21. See the Schedule 2 page and the self-employment tax page.

Edition and line numbers

This page reads the 2025 Form 1040 and its 2025 instructions, the current files irs.gov served on 2026-10-17. They are the forms for the tax year 2025 return, filed in 2026. The instructions say “The lines on Forms 1040 and 1040-SR are the same.” so everything here applies to Form 1040 and to Form 1040-SR alike. The method names and the three check boxes are as quoted above. Check the tax year printed on the form you are filling in and use the line numbers on that year’s form, because a different year’s form can number or word its lines differently.

Common mistakes

• Using the Tax Table when another worksheet applies. The instructions say “don’t use the Tax Table or Tax Computation Worksheet to figure your tax if any of the following applies.”
• Figuring the tax before finishing line 15. The worksheet says “complete Form 1040 or 1040-SR through line 15.”
• Leaving off a box. The instructions say, for Form 8814, “Check the appropriate box.” The same words appear for Form 4972.

Related: Qualified dividends and capital gain tax worksheet, Capital gains tax calculator, Form 8814, Schedule 2 (Form 1040), and 2025 tax brackets.

Sources

• Instructions for Form 1040 and Form 1040-SR (2025): https://www.irs.gov/pub/irs-pdf/i1040gi.pdf
• Form 1040, U.S. Individual Income Tax Return (2025): https://www.irs.gov/pub/irs-pdf/f1040.pdf

Read from the IRS documents linked above on October 17, 2026. General information, not tax advice. Your own facts decide the outcome, and a preparer, the account provider or the IRS is the right place to confirm anything consequential.