Income Tax Calculator
Estimate your US federal income tax liability by entering your annual gross income, filing status, and standard deduction — the calculator subtracts the deduction and applies a simplified single rate per filing status. A back-of-envelope tool; for accurate progressive bracket math use the full bracket calculator.
Last updated: May 2026
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About this calculator
The formula is tax = max(0, (income − standardDeduction) × rate), where rate is 10% for single, 12% for married-filing-jointly/separately and head-of-household, and 22% otherwise (a fallback for unrecognized filing statuses). This is a deliberately simplified flat-rate approximation, NOT a faithful model of US progressive brackets. Real US federal income tax uses seven brackets (10/12/22/24/32/35/37) that apply to consecutive slices of taxable income — so a single filer with $80,000 of taxable income does NOT pay 10% across the board, they pay 10% on the first $11,000, 12% on the next $33,725, and 22% on the rest, for an effective rate of around 13.5%. The flat-rate model in this calculator works reasonably well for low-income filers who fall entirely inside one bracket (single filers under $11,000 of taxable income are entirely in 10%; under $44,725 in 12%; etc.), but for middle and high earners it understates tax substantially. Taxable income equals gross income minus above-the-line deductions (traditional 401(k), traditional IRA, HSA, SE-tax deduction, student-loan interest) minus the standard deduction OR itemized deductions (whichever is larger). 2024 standard deductions: $14,600 single, $29,200 MFJ, $21,900 HoH. The calculator does not model tax credits (CTC, EITC, AOTC, premium tax credit), which are a separate layer that reduces tax owed dollar-for-dollar. It does not model FICA (payroll tax), state tax, AMT, capital gains rates, NIIT, or QBI deduction. Edge cases: income below the standard deduction returns zero tax (correct in the real system too — no income tax owed below the deduction); negative deductions would mathematically increase tax (real-world deductions are always non-negative).
How to use
Example 1 — Single filer at low-moderate income (calculator's sweet spot). You earn $30,000 gross in 2024, take the $14,600 standard deduction, and have single filing status. Enter income = 30000, filingStatus = single, standardDeduction = 14600, taxYear = 2024. Result: (30000 − 14600) × 0.10 = 1540 → $1,540. Verify against real brackets: taxable income of $15,400 falls entirely in single 10% bracket up to $11,600 plus 12% on the next $3,800, so real tax = 11600 × 0.10 + 3800 × 0.12 = 1160 + 456 = $1,616. Calculator estimate $1,540 vs real $1,616 → off by $76 (4.7%). For low earners the flat-10% approximation is roughly correct but missing the 12%-bracket spillover. Example 2 — MFJ filer at moderate income (where the simplification breaks). You earn $100,000 gross in 2024, take the $29,200 standard deduction, married-filing-jointly. Enter income = 100000, filingStatus = marriedJoint, standardDeduction = 29200, taxYear = 2024. Result: (100000 − 29200) × 0.12 = 8496 → $8,496. Real bracket math for $70,800 of taxable income MFJ: 10% on first $23,200 = $2,320, 12% on next $47,600 = $5,712. Total = $8,032. Calculator estimate $8,496 vs real $8,032 → overstates by $464 (5.8%). The error grows quickly above $94,300 of taxable income MFJ where the 22% bracket kicks in and the flat 12% understates dramatically — at $200k MFJ this calculator gives roughly $20,500 vs real ~$25,000, a $4,500 underestimate. Bottom line: use for rough budgeting only and verify with full bracket math for any real planning.
Frequently asked questions
Why does this calculator give the wrong answer for high earners?
Because it applies a single flat rate (10% for single, 12% for everyone else) to taxable income, while the real US federal income tax is progressive with seven brackets (10/12/22/24/32/35/37). For a single filer earning under $11,600 (2024 taxable) the flat 10% is exactly right. From $11,600 to $47,150 the real system uses 12% on the portion above $11,600, so the flat-10% understates. Above $47,150 the 22% bracket kicks in, then 24% above $100,525, 32% above $191,950, 35% above $243,725, 37% above $609,350 — so for any filer in the 22%+ bracket, this calculator's flat-rate estimate diverges from reality by an amount that grows with income. The simplification is acceptable for rough budgeting at low-to-moderate incomes but unsuitable for any planning decision. Use the tax-bracket calculator or full tax software for accurate progressive-bracket math.
What is the standard deduction and should I take it?
The standard deduction is a fixed dollar amount subtracted from your gross income before tax is calculated — a tax-free baseline of income. For 2024: $14,600 single, $29,200 MFJ, $21,900 head of household, $14,600 married-filing-separately. The alternative is itemizing on Schedule A: adding up state and local taxes (capped at $10,000 — the SALT cap), mortgage interest on up to $750k of acquisition debt, charitable contributions (cash up to 60% of AGI, appreciated stock up to 30%), medical expenses above 7.5% of AGI, and a few smaller categories. Take whichever is LARGER. Since the Tax Cuts and Jobs Act doubled the standard deduction in 2018, roughly 87% of filers now take the standard. Itemizing is most common for high-income homeowners with mortgages in high-tax states (California, New York, New Jersey) where SALT + mortgage interest can exceed the standard. Charitable bunching (concentrating multiple years of donations into one year to itemize that year and take standard in alternate years) is a tax-planning move that comes from this threshold.
What is gross income vs taxable income?
Gross income is all the money you received during the year from every source — wages (W-2 box 1), self-employment net earnings, interest, dividends, capital gains, rental income, retirement distributions, Social Security (partially), unemployment, gambling winnings, alimony from pre-2019 divorces, business income, royalties, etc. The IRS includes some surprising items (the value of barter exchanges, illegal income, treasure-trove finds — see Pub 17) and excludes others (gifts, inheritances, life insurance proceeds, qualified scholarship aid, employer-paid health insurance premiums, Roth distributions in retirement, return of capital). Adjusted Gross Income (AGI) is gross income minus above-the-line deductions: traditional 401(k) contributions (employer-side already excluded from box 1, but Schedule C self-employed contributions are above-the-line), traditional IRA contributions (income-limited), HSA contributions (income-unlimited), half of self-employment tax, student-loan interest up to $2,500, educator expenses up to $300. Taxable income is AGI minus the standard deduction (or itemized) minus the qualified business income deduction. This calculator subtracts only the standard deduction, treating "income" as if it equals AGI — close enough for many W-2 filers but inaccurate for anyone with above-the-line items beyond the standard deduction.
What is missing from this calculator vs. real tax?
Many things. (1) Progressive brackets — this is the biggest gap (see above). (2) Tax credits — Child Tax Credit ($2,000/child with up to $1,700 refundable), EITC ($632 to $7,830 depending on income and kids), Saver's Credit, American Opportunity Credit (up to $2,500/student), Lifetime Learning Credit, Premium Tax Credit, Clean Vehicle Credit, residential energy credits — credits reduce tax owed dollar-for-dollar and can produce refunds even when withholding is zero. (3) Payroll tax (FICA) — Social Security 6.2% + Medicare 1.45% = 7.65% on wages up to $168,600 (SS), plus 0.9% Additional Medicare above $200k single/$250k MFJ. (4) Self-Employment tax for 1099 income (15.3% on 92.35% of net SE earnings). (5) State and local income tax — varies from 0% (TX/FL/WA/NV/SD/WY/AK/TN/NH) to 13.3% (CA top bracket). (6) Net Investment Income Tax (3.8% on net investment income for high earners). (7) AMT (Alternative Minimum Tax) — separate parallel calculation that can override regular tax for taxpayers with large preference items. (8) Long-term capital gains and qualified dividends — taxed at 0/15/20% instead of ordinary brackets. (9) QBI deduction for pass-through business income (20% of qualifying income). (10) Phaseouts of deductions and credits. The calculator's flat-rate is a rough thumbnail, not a tax return.
When should I not use this calculator?
Skip it for any income above ~$50k where progressive brackets diverge from the flat-rate approximation by hundreds to thousands of dollars. Skip it for tax planning decisions involving real dollars (Roth conversions, capital-gain harvesting, charitable bunching, mortgage prepayment, equity-comp exercises) — use the tax-bracket calculator to get your true marginal rate, then use full tax software for liability. Skip it for self-employed filers — Self-Employment tax is 15.3% on top of income tax and dominates the bill at moderate incomes. Skip it for retirees — Social Security taxation rules (0%, 50%, or 85% taxable depending on combined income) and required minimum distribution (RMD) interactions are not captured. Skip it for investors with significant capital gains, qualified dividends, or NIIT exposure — wrong brackets. Skip it for anyone subject to AMT or with large itemized deductions. For accurate tax estimation use the IRS Tax Withholding Estimator (irs.gov/withholding), TurboTax/FreeTaxUSA/H&R Block/TaxAct, or a CPA. This tool's value is purely a rough thumbnail for low-income, single-source-of-income W-2 filers.