In Short
Federal income tax is figured on taxable income: your income minus pre-tax 401(k) and HSA contributions, minus the standard deduction ($16,100 single, $32,200 married filing jointly for 2026), taxed in brackets from 10% to 37% [1][2]. A single filer earning $75,000 in 2026 has $58,900 of taxable income and owes $7,670, an effective rate of about 10% and a top bracket of 22%. With $8,000 withheld, that's a $330 refund.
How to Use the Income Tax Calculator
- Enter your wages and any other income, your filing status and your state.
- Add pre-tax 401(k) and HSA contributions, and itemized deductions if you have them.
- Enter the number of children under 17 and the federal tax withheld so far.
- Or tap Say It All: “My wife and I earned 150k in wages in Ohio with 2 kids and we put 10,000 in our retirement plan and had 14,000 withheld.”
- Read the bracket table to see how each slice of income is taxed.
The Formula
Each rate applies only to the income inside its bracket, which is why your effective rate is always below your top bracket.
- Adjusted gross income = wages − pre-tax 401(k) − HSA + other income
- Taxable income = AGI − the larger of the standard deduction and itemized deductions
- Tax = the sum of (income in each bracket × that bracket's rate)
- Child tax credit = $2,200 per child, less $50 per $1,000 of AGI above $200,000 ($400,000 joint); up to $1,700 per child refundable
- Refund (or amount owed) = withholding + refundable credit − tax after credits
Worked Examples
| Scenario | Inputs | Result |
|---|---|---|
| Single, $75,000 salary | Standard deduction, $8,000 withheld | Taxable $58,900 · tax $7,670 · 22% bracket · 10.2% effective · refund $330 |
| Married filing jointly, two children | $150,000 wages, $10,000 to a 401(k), $14,000 withheld | Taxable $107,800 · tax $13,140 − $4,400 child credit = $8,740 · refund $5,260 |
| Single, $100,000 salary | Standard deduction, nothing withheld | Taxable $83,900 · tax $13,170 · 22% bracket · 13.2% effective |
| Head of household, two children | $45,000 wages, $1,500 withheld | Tax $2,148 wiped out by the credit · $2,252 refundable · refund $3,752 |
Illustrative examples, not projections. Figures use the tax year shown and the assumptions above.
How Do Tax Brackets Work?
The US taxes income in layers. For a single filer in 2026, the first $12,400 of taxable income is taxed at 10%, the next slice up to $50,400 at 12%, then 22% up to $105,700, and so on up to 37% [1][3]. Moving into a higher bracket only raises the rate on the dollars inside it.
That's why the calculator shows two rates. The marginal rate is the bracket your last dollar falls in, which is what an extra dollar of income or deduction is worth. The effective rate is your total tax divided by your total income.
Standard Deduction or Itemize?
Everyone gets the larger of the two. For 2026 the standard deduction is $16,100 single, $32,200 married filing jointly and $24,150 head of household [1][4]. Itemizing (mortgage interest, state and local taxes, gifts to charity, large medical bills) only helps when the total is bigger. The calculator compares them for you.
Pre-tax 401(k) and HSA contributions come off before either, which is why they lower tax at your marginal rate.
How Does the Child Tax Credit Work in 2026?
It is up to $2,200 per qualifying child under 17, and it lowers tax dollar for dollar [1][5]. Above $200,000 of income ($400,000 married filing jointly) it shrinks by $50 for each $1,000 [6]. If the credit is more than your tax, up to $1,700 per child can be paid as a refund, limited to 15% of earned income above $2,500 [5][6].
Frequently Asked Questions
How much federal tax do I pay on $50,000?
A single filer with $50,000 of wages in 2026 has $33,900 of taxable income after the $16,100 standard deduction and owes $3,820, an effective rate of 7.6%.
How much federal tax do I pay on $100,000?
A single filer with $100,000 of wages in 2026 owes $13,170 on $83,900 of taxable income. The top bracket is 22%; the effective rate is 13.2%.
What tax bracket am I in?
It depends on taxable income, not gross pay. For 2026, a single filer is in the 22% bracket from $50,401 to $105,700 of taxable income, and a joint filer from $100,801 to $211,400 [1].
Why do I owe taxes instead of getting a refund?
Usually because withholding was lower than the tax: a second job, side income with no withholding, a bonus, or a W-4 that doesn't match your situation. Enter your withholding to see the gap.
Does this include state income tax?
It uses each state's brackets as the state table is filled in, and says so when a state isn't included yet. City and county income taxes are explained, not calculated.
Sources
- Rev. Proc. 2025-32: 2026 inflation adjustments (brackets, standard deduction, capital gains, QBI, child tax credit) — Internal Revenue Service
- IRS releases tax inflation adjustments for tax year 2026, including amendments from the One Big Beautiful Bill — Internal Revenue Service
- Federal income tax rates and brackets — Internal Revenue Service
- Topic no. 501, Should I itemize? — Internal Revenue Service
- Child tax credit — Internal Revenue Service
- About Schedule 8812, Credits for Qualifying Children and Other Dependents — Internal Revenue Service
Official sources only: the IRS, SSA, BLS and other government agencies. Read how Zentavos researches.