Form 1040 Line 14: Calculating Your Tax
Where Line 14 Comes From
You arrive at Line 14 by starting with your taxable income on Line 15 (yes, the line numbers seem backwards—Line 15 feeds Line 14 because Schedule 2 adjustments get added afterward). Your taxable income is AGI minus either the standard deduction or itemized deductions, minus the qualified business income deduction if applicable.
From that taxable income figure, you compute the tax using one of several methods. Which method depends on the type of income you earned and how much.
Tax Tables vs. Tax Computation Worksheet
If your taxable income is under $100,000, you look it up in the tax table printed in the Form 1040 instructions. The table gives you a flat dollar amount for income ranges in $50 increments. It’s pre-calculated so you don’t have to do bracket math yourself.
Above $100,000, you switch to the Tax Computation Worksheet. This walks you through the marginal bracket calculation directly. For 2025, the brackets for a single filer look like this:
- 10% on income up to $11,925
- 12% from $11,926 to $48,475
- 22% from $48,476 to $103,350
- 24% from $103,351 to $197,300
- 32% from $197,301 to $250,525
- 35% from $250,526 to $626,350
- 37% above $626,350
A persistent myth: people think earning one more dollar can push all their income into a higher bracket. It can’t. Only the income above each threshold is taxed at the higher rate. Someone earning $103,351 pays 22% on exactly one dollar, not on $103,351.
The Qualified Dividends and Capital Gains Tax Worksheet
Here’s where Line 14 gets more complex than most people realize. If you have qualified dividends or net long-term capital gains, you don’t just run everything through the ordinary brackets. Instead, you use the Qualified Dividends and Capital Gain Tax Worksheet in the Form 1040 instructions.
This worksheet effectively stacks your income: ordinary income fills the lower brackets first, then your qualified dividends and long-term gains sit on top—but they’re taxed at preferential rates (0%, 15%, or 20% depending on your total taxable income). For 2025, single filers pay 0% on long-term gains up to $48,475 of taxable income, 15% up to $533,400, and 20% above that.
The result can be surprising. A retiree with $40,000 in qualified dividends and no other income might owe zero federal tax—because the entire amount falls within the 0% capital gains bracket after the standard deduction.
The Net Investment Income Tax
On top of the regular tax from Line 14, higher earners face the 3.8% Net Investment Income Tax (NIIT) under IRC § 1411. It applies to the lesser of your net investment income or the amount by which your MAGI exceeds $200,000 (single) or $250,000 (married filing jointly). This isn’t computed on Line 14 itself—it shows up on Schedule 2—but it’s part of the total tax picture and catches people off guard when they sell a home or have a big capital gain year.
Alternative Minimum Tax (AMT)
The AMT is a parallel tax system. You calculate your tax two ways—regular and AMT—and pay whichever is higher. The AMT disallows certain deductions (state and local taxes, for instance) and adds back preference items like ISO exercises. For 2025, the AMT exemption is $88,100 for single filers and $137,000 for married filing jointly.
After the 2017 Tax Cuts and Jobs Act raised the exemption amounts, far fewer people owe AMT than before. But it still bites in specific situations: large ISO exercises, significant state tax deductions that get added back, or high miscellaneous income. The AMT amount, if any, gets added to your regular tax and the combined figure appears on Line 14 via Form 6251 flowing through Schedule 2.
A Counterintuitive Observation
Two taxpayers with identical taxable incomes can have very different Line 14 amounts. Consider two single filers, each with $200,000 in taxable income. Taxpayer A earned it all as salary. Taxpayer B earned $100,000 in salary and $100,000 in long-term capital gains. Taxpayer B’s Line 14 will be thousands of dollars lower because half the income is taxed at preferential capital gains rates instead of ordinary rates. The form number is the same, the taxable income is the same, but the composition of that income changes the tax.
How Line 14 Connects Forward
Line 14 is the starting point for your total tax liability. From here, nonrefundable credits on Line 18 reduce it (but can’t take it below zero). Then other taxes on Line 21—self-employment tax, additional Medicare tax, and more—get added to produce your total tax on Line 22. Understanding what built Line 14 helps you see where planning opportunities exist: shifting income character, timing capital gains, or bunching deductions to change which worksheet applies.
Sources & References
Related Services
Sources and Further Reading
Need help with your tax return?
Start with a fee estimate, or request a consultation if you’re ready to engage.