How federal income tax is calculated
Tax = Σ (income in each bracket × that bracket's rate) − credits
The US uses progressive brackets: each rate applies only to the slice of taxable income inside its bracket. Moving into a higher bracket never makes your whole income taxed at the higher rate.
2026 federal tax brackets
| Rate | Single | Married filing jointly | Head of household | Married filing separately |
|---|---|---|---|---|
| 10% | $0 – $12,400 | $0 – $24,800 | $0 – $17,700 | $0 – $12,400 |
| 12% | $12,400 – $50,400 | $24,800 – $100,800 | $17,700 – $67,450 | $12,400 – $50,400 |
| 22% | $50,400 – $105,700 | $100,800 – $211,400 | $67,450 – $105,700 | $50,400 – $105,700 |
| 24% | $105,700 – $201,775 | $211,400 – $403,550 | $105,700 – $201,750 | $105,700 – $201,775 |
| 32% | $201,775 – $256,225 | $403,550 – $512,450 | $201,750 – $256,200 | $201,775 – $256,225 |
| 35% | $256,225 – $640,600 | $512,450 – $768,700 | $256,200 – $640,600 | $256,225 – $384,350 |
| 37% | over $640,600 | over $768,700 | over $640,600 | over $384,350 |
Amounts are taxable income. Qualifying surviving spouses use the married filing jointly column.
2026 standard deduction
| Filing status | Standard deduction | Extra if 65+ or blind (each) |
|---|---|---|
| Single or married filing separately | $16,100 | $2,050 single · $1,650 married |
| Married filing jointly | $32,200 | $1,650 |
| Head of household | $24,150 | $2,050 |
Senior deduction (2025–2028): each person 65 or older can also deduct up to $6,000, whether or not they itemize. It shrinks by 6% of modified AGI over $75,000 ($150,000 on a joint return). Married couples must file jointly to claim it.
Child tax credit: $2,200 per child under 17 and $500 per other dependent. The credit drops by $50 for each $1,000 (or part of $1,000) of AGI over $200,000 ($400,000 joint). Up to $1,700 per child can be refunded even if you owe no tax, limited to 15% of earned income over $2,500.
Worked example
A single filer earns $85,000 and puts $5,000 in a 401(k). AGI is $80,000. Taking the $16,100 standard deduction leaves $63,900 of taxable income.
- 10% of the first $12,400 = $1,240
- 12% of the next $38,000 ($12,400 to $50,400) = $4,560
- 22% of the last $13,500 ($50,400 to $63,900) = $2,970
Total tax: $8,770. The marginal rate is 22%, but the effective rate is 8,770 ÷ 85,000 = 10.3%.
Getting married or comparing two returns? The marriage tax calculator compares two single returns with one joint return.
What this calculator leaves out
- State and local income tax isn't included. This is federal income tax only.
- Social Security and Medicare (FICA) taxes aren't included. The take-home pay calculator adds them.
- Credits other than the child tax credit and credit for other dependents (earned income credit, education and energy credits and so on).
- Capital gains and qualified dividends taxed at 0%, 15% or 20%, the alternative minimum tax, the 3.8% net investment income tax and self-employment tax.
- The new deductions for tips, overtime and car loan interest (2025–2028). Subtract them from income yourself as pre-tax deductions if you qualify.
- The 2026 limit on itemized deductions for people in the 37% bracket, and the cap on state and local tax (SALT) deductions. Enter itemized deductions after the SALT cap.
- The refundable child credit uses your total income as earned income, and skips the alternative rule for families with three or more children.
- Below $100,000 of taxable income, the IRS tax table works in small steps ($50 for most incomes), so your return can differ from this by a few dollars.
Sources
- IRS Rev. Proc. 2025-32 – 2026 tax rate tables, standard deduction, extra amount for 65+ or blind, child tax credit amounts
- IRS news release IR-2025-103 – summary of the 2026 figures
- IRS: enhanced deduction for seniors – $6,000 senior deduction, 2025–2028
- Schedule 1-A (Form 1040) – senior deduction worksheet: 6% phase-out above $75,000 / $150,000
- IRS: Working Families Tax Cuts provisions for individuals – tips, overtime and senior deductions
- IRS: Child Tax Credit
- Schedule 8812 (Form 1040) – credit phase-out and refundable credit worksheet