USA Income Tax Calculator 2024

How US federal income tax works

The USA uses a progressive income tax system, where your income is taxed at different rates depending on which tax bracket it falls into. The higher your income, the higher the marginal rate on that portion — but your effective tax rate (total tax ÷ total income) is always lower than your marginal rate because earlier income is taxed at lower rates.

2024 Federal Tax Brackets (single filer)

• 10% on income up to $11,600
• 12% on $11,600–$47,150
• 22% on $47,150–$100,525
• 24% on $100,525–$191,950
• 32% on $191,950–$243,725
• 35% on $243,725–$609,350
• 37% on $609,350 and above

These rates apply to taxable income (gross income minus the standard deduction).

Standard Deduction

In 2024, single filers get a standard deduction of $14,600. This amount is subtracted from your gross income before calculating tax. You don't need receipts — it's automatic. If you have significant itemized deductions (mortgage interest, charitable donations, state/local taxes), you might itemize instead, but most people benefit from the standard deduction.

FICA Taxes (Social Security and Medicare)

On top of federal income tax, W-2 employees have FICA taxes withheld:

• Social Security: 6.2% on wages up to $168,600 (2024 wage base). Once you hit the cap, no more Social Security tax for that year.
• Medicare: 1.45% on all wages, with no cap. High-income earners (over $200k for single filers) pay an additional 0.9% Medicare tax.

Your employer matches these amounts, but only your portion appears in your take-home calculation. Self-employed individuals pay both employee and employer portions (15.4% combined).

Tax brackets explained

The brackets are cumulative, not absolute. For example, at a $50,000 salary:

• First $11,600 taxed at 10% = $1,160
• Next $35,400 ($47,150 − $11,600) taxed at 12% = $4,248
• Remaining $2,850 ($50,000 − $47,150) taxed at 22% = $627
• Total tax = $6,035 (effective rate ≈ 12.1%)

Your marginal rate (22%) is what you'd pay on the next dollar earned. Your effective rate (12.1%) is what you actually paid on average.

What this calculator does NOT include

This is a simplified calculation. It does not account for:

• State and local income tax — varies by state; 9 states have no income tax
• Tax credits — EITC, Child Tax Credit, education credits, etc. (can reduce tax owed significantly)
• Itemized deductions — only the standard deduction is used
• Above-the-line deductions — student loan interest, 401(k) contributions, HSA contributions, etc.
• Capital gains and investment income — taxed differently than wages
• Self-employment tax — for 1099 contractors (15.4% combined Social Security + Medicare on net earnings)
• Married filing status — this calculator assumes single filer; brackets differ for married filing jointly or head of household
• Medicare surtax — additional 0.9% Medicare tax on high earners (over $200k single)
• Filing status variations — dependent status, age over 65 (higher standard deduction), etc.

For accurate tax planning, use the official IRS calculator at irs.gov or consult a tax professional (CPA or tax attorney).