How Federal Income Tax Works
The U.S. uses a progressive tax system. That means your income gets divided into slices, each taxed at a different rate. Only the income within each range is taxed at that bracket's rate, not your entire income.
For example, a single filer earning $80,000 in 2025 doesn't pay 22% on all $80,000. The first $11,925 is taxed at 10%, the next chunk at 12%, and only the portion above $48,475 gets the 22% rate. This is why your effective rate is always lower than your marginal bracket.
2025 Federal Tax Brackets
Single Filers
| Tax Rate | Income Range |
|---|---|
| 10% | $0 – $11,925 |
| 12% | $11,926 – $48,475 |
| 22% | $48,476 – $103,350 |
| 24% | $103,351 – $197,300 |
| 32% | $197,301 – $250,525 |
| 35% | $250,526 – $626,350 |
| 37% | $626,351+ |
Married Filing Jointly
| Tax Rate | Income Range |
|---|---|
| 10% | $0 – $23,850 |
| 12% | $23,851 – $96,950 |
| 22% | $96,951 – $206,700 |
| 24% | $206,701 – $394,600 |
| 32% | $394,601 – $501,050 |
| 35% | $501,051 – $751,600 |
| 37% | $751,601+ |
Standard Deduction vs. Itemizing
The standard deduction reduces your taxable income by a fixed amount based on filing status. For 2025, it's $15,000 (single), $30,000 (married jointly), or $22,500 (head of household).
Itemizing makes sense when your deductible expenses add up to more than the standard amount. Common itemized deductions include mortgage interest, state and local taxes (capped at $10,000), and charitable contributions.
Ways to Lower Your Tax Bill
- Contribute to a traditional 401(k) or IRA to reduce taxable income
- Max out your HSA if you have a high-deductible health plan
- Claim eligible tax credits (child tax credit, education credits, earned income credit)
- Bunch charitable donations into one year to exceed the standard deduction
- Consider tax-loss harvesting on investment losses
Marginal vs. Effective Tax Rate
Your marginal rate is the bracket applied to your last dollar of income. Your effective rate is the total tax divided by total income. If you earn $80,000 as a single filer, your marginal rate is 22%, but your effective rate is closer to 14%. The effective rate is what actually matters for financial planning.
Pre-Tax Deductions That Save You Money
Certain deductions come out before your income gets taxed. A 401(k) contribution of $23,500 (the 2025 limit) directly reduces your taxable income by that amount. If you're in the 22% bracket, that's roughly $5,170 in tax savings per year, plus your retirement account grows.
HSA contributions work the same way. The 2025 limit is $4,300 for individuals and $8,550 for families. This money goes in pre-tax, grows tax-free, and comes out tax-free for medical expenses.
State Income Tax Overview
Your total tax burden depends heavily on where you live. Nine states have no state income tax: Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, and Wyoming. On the other end, California tops out above 13%. Moving from California to Texas on a $100,000 salary could save over $8,000/year in state taxes alone.
When comparing job offers across states, convert the salary to hourly using our salary converter, then factor in state tax differences and cost of living. A lower salary in a no-tax state can leave you with more take-home pay than a higher salary in a high-tax state.
Effective Federal Tax Rate by Income (Single Filer, 2025)
Effective rate is total tax ÷ gross income. Standard deduction applied.
Common Tax Credits to Reduce Your Bill
Tax credits reduce your tax bill dollar-for-dollar, making them more valuable than deductions:
- Earned Income Tax Credit (EITC): Worth up to $7,830 for low-to-moderate income workers with children (2025).
- Child Tax Credit: $2,000 per qualifying child under 17, with $1,700 refundable.
- American Opportunity Credit: Up to $2,500/year for eligible college students (first 4 years).
- Saver’s Credit: Up to $1,000 ($2,000 for couples) for low-income retirement contributions.
- EV Tax Credit: Up to $7,500 for qualifying new electric vehicles.