US Federal Income Tax Calculator (2025)

Understanding Your 2025 Federal Income Tax

In the United States, the federal government uses a "marginal" or "progressive" tax system. This means that as your income increases, you move into higher tax brackets, but only the income *within* that bracket is taxed at that higher rate. This calculator helps you estimate your total federal tax bill for the 2025 tax year (the return you file in 2026).

What are Tax Brackets?

A tax bracket is a range of income taxed at a specific rate. For example, in 2025, a Single filer pays 10% on their first $11,600 of *taxable* income. If they earn more, they pay 12% on the income between $11,601 and $47,150, and so on. You never lose money by moving to a higher tax bracket; only the additional dollars are taxed at the new, higher rate. Your "Marginal Tax Rate" is the highest bracket your income falls into.

Standard vs. Itemized Deductions

Before calculating your tax, you get to reduce your gross income by taking a deduction. You can choose one of two methods:

• Standard Deduction: A fixed dollar amount set by the IRS based on your filing status (e.g., $14,600 for Single in 2025). Most taxpayers use this because it's simple and often higher.
• Itemized Deductions: A sum of specific deductible expenses, such as state and local taxes (SALT) up to $10,000, home mortgage interest, and charitable donations. You should only itemize if your total itemized deductions are *greater* than your standard deduction.

What is FICA Tax?

FICA tax is a separate payroll tax used to fund Social Security and Medicare. It's automatically deducted from your paycheck. This calculator includes it because it's a significant part of your total tax burden. It includes:

• Social Security: 6.2% on income up to $177,700 (the 2025 wage base).
• Medicare: 1.45% on all your earnings, plus an additional 0.9% on income over $200,000 (for Single filers).