Enter Values
2025 Standard Deductions
| Filing Status | Deduction |
|---|---|
| Single | $15,000 |
| Married Filing Jointly | $30,000 |
| Married Filing Separately | $15,000 |
| Head of Household | $22,500 |
Tax Results
Formula Breakdown
Tax Visualizations
Income by Tax Bracket
Rate Comparison
Income Breakdown
Model Assumptions
- Uses 2025 federal tax brackets and standard deduction amounts only
- Assumes all income is ordinary income (W-2 wages from a single earner)
- Does not include state or local income taxes
- Standard deduction amounts are for non-dependent filers under age 65
- FICA estimated at employee share only (6.2% SS + 1.45% Medicare)
- Social Security wage base cap: $176,100 (2025)
- Does not include Additional Medicare Tax (0.9% above $200K/$250K)
- Does not account for AMT, NIIT, or QBI deduction
- Does not model tax credits (Child Tax Credit, EITC, etc.)
- Pre-tax retirement contributions reduce federal income tax only, not FICA
For educational purposes. Not tax advice. Consult a CPA for personalized tax planning.
Understanding Marginal vs. Effective Tax Rates
How Progressive Tax Brackets Work
The U.S. federal income tax system is progressive, meaning higher income is taxed at higher rates. However, a common misconception is that moving into a higher bracket means all your income is taxed at that rate. In reality, only the income within each bracket is taxed at that bracket's rate.
Marginal vs. Effective Rate
Marginal Rate
The rate on your last dollar of taxable income. This is the highest bracket you reach. It matters most for decisions about earning additional income.
Effective Rate
The average rate you pay across all brackets. Always lower than your marginal rate. This is your true tax burden as a percentage of gross income.
How Retirement Contributions Reduce Taxes
Pre-tax retirement contributions (401(k), 403(b), deductible Traditional IRA) reduce your Adjusted Gross Income (AGI), which lowers your taxable income. The tax savings equal the reduction in federal tax from the lower taxable income. For example, contributing $6,000 when your marginal rate is 22% saves approximately $1,320 in federal taxes. However, these contributions do not reduce FICA taxes.
Frequently Asked Questions
Disclaimer
This calculator is for educational purposes only and uses simplified federal tax models. It assumes all income is ordinary W-2 wages and does not account for state/local taxes, tax credits, AMT, NIIT, qualified dividends, long-term capital gains rates, or self-employment tax. Consult a qualified CPA or tax professional for personalized tax planning advice. This tool should not be used for tax filing or financial decisions.
