'I turned down the raise because it would have bumped me into a higher tax bracket.' This sentence, said in good faith every payday across the country, is based on a misunderstanding of how the US income tax system actually works. Moving into a higher bracket never reduces your take-home pay. Understanding why is the single most valuable piece of tax literacy most people will ever learn.
This guide unpacks tax brackets, the difference between marginal and effective rates, how filing status changes everything, and how to use our Income Tax Calculator to estimate your real tax bill.
What a Tax Bracket Actually Is
The US uses a progressive marginal tax system. That means your income is divided into slices, and each slice is taxed at its own rate. When people say 'I am in the 24% bracket,' what they mean is that the last dollar they earned is taxed at 24%. Every dollar below that threshold is taxed at a lower rate.
Think of it as a staircase. The first step is narrow and cheap. Each higher step charges more per dollar, but only on the portion of income sitting on that step. Nothing you earn ever causes your earlier income to be re-taxed at a higher rate.
Marginal vs Effective Rate: The Core Concept
Two numbers matter when people talk about tax rates:
- Marginal rate: the rate applied to your next dollar of income
- Effective rate: your total tax divided by your total income
These are almost never the same. The marginal rate is always higher than the effective rate in a progressive system, because only the top slice of income is taxed at the marginal rate while everything below is taxed less.
A single filer earning $85,000 in 2025 has a marginal rate of 22% but an effective federal rate closer to 12%. That is not a typo. The effective rate is what actually came out of your paycheck. The marginal rate is what matters when you are deciding whether to take on extra work, contribute to a pre-tax 401(k), or sell an investment.
The Standard Deduction
Before any bracket applies, you subtract a standard deduction from your gross income. For 2025:
| Filing Status | 2025 Standard Deduction |
|---|---|
| Single | $15,000 |
| Married Filing Jointly | $30,000 |
| Head of Household | $22,500 |
| Married Filing Separately | $15,000 |
So a single filer earning $85,000 has taxable income of $70,000 ($85,000 - $15,000). The brackets apply to that $70,000, not the $85,000. This is why people who 'make $50,000' but have no deductions actually owe federal tax on roughly $35,000.
Itemizing (mortgage interest, state tax up to $10,000, charity) only makes sense when those deductions exceed the standard deduction. After the 2018 tax law, most filers take the standard deduction.
2025 Federal Brackets
For a single filer in 2025:
| Rate | Taxable Income Range (Single) |
|---|---|
| 10% | $0 to $11,925 |
| 12% | $11,925 to $48,475 |
| 22% | $48,475 to $103,350 |
| 24% | $103,350 to $197,300 |
| 32% | $197,300 to $250,525 |
| 35% | $250,525 to $626,350 |
| 37% | Over $626,350 |
(Figures are indexed each year for inflation. Our calculator uses the current published IRS values.)
Worked Example: Single Filer, $85,000 Gross
Let's compute the federal tax step by step.
- Gross income: $85,000
- Standard deduction: $15,000
- Taxable income: $70,000
Now apply the brackets:
| Bracket | Slice of Income | Rate | Tax |
|---|---|---|---|
| 10% | $0 to $11,925 | 10% | $1,192.50 |
| 12% | $11,925 to $48,475 ($36,550) | 12% | $4,386.00 |
| 22% | $48,475 to $70,000 ($21,525) | 22% | $4,735.50 |
| Total federal tax | $10,314 |
- Marginal rate: 22% (the rate on the last dollar)
- Effective federal rate: $10,314 / $85,000 = 12.1%
If this filer takes on a $5,000 side project, every dollar of that $5,000 is taxed at 22% (not 12.1%), because it sits on top of existing income. That is the marginal rate doing work.
How Filing Status Changes Everything
Same $85,000 income, different filing status:
| Filing Status | Standard Deduction | Taxable Income | Federal Tax | Effective Rate |
|---|---|---|---|---|
| Single | $15,000 | $70,000 | $10,314 | 12.1% |
| Married Filing Jointly | $30,000 | $55,000 | $6,197 | 7.3% |
| Head of Household | $22,500 | $62,500 | $7,825 | 9.2% |
Filing jointly on a single $85,000 income saves over $4,100 in federal tax versus filing single. This is the much-discussed 'marriage bonus,' which applies when incomes are unequal. When both spouses earn similar high incomes, you can see a small 'marriage penalty' at the top brackets instead.
The State Income Tax Layer
Federal tax is only part of the picture. Most states also charge income tax, from 0% in nine states (TX, FL, TN, NV, WA, WY, SD, AK, NH for wages) to over 13% at the top in California.
Some states use flat rates, others use their own progressive brackets, and a few have very different treatment of retirement income. Our Income Tax Calculator covers federal plus all 50 states so you can see your combined effective rate in one place, which is especially useful when comparing job offers across states.
FICA: The Flat-Until-Cap Payroll Tax
On top of income tax, wage earners pay FICA:
- Social Security: 6.2% on wages up to the annual cap ($176,100 for 2025)
- Medicare: 1.45% on all wages (no cap)
Your employer pays a matching 6.2% and 1.45% behind the scenes. If you are self-employed, you pay both halves (15.3% combined) but get to deduct half as a business expense.
Our $85,000 single filer pays:
- Social Security: $5,270
- Medicare: $1,232
- Total FICA: $6,502
Adding federal income tax, total federal-level tax is about $16,816 on $85,000, or a combined effective rate of 19.8%. This is the number that actually reflects what comes out of your paycheck federally.
Additional Medicare Tax for High Earners
If your wages exceed $200,000 (single) or $250,000 (MFJ), an extra 0.9% Medicare tax applies to the amount above the threshold. There is also a 3.8% Net Investment Income Tax on investment income for high earners. These are small in dollar terms for most households but can meaningfully shift the marginal calculation for top earners.
Pre-Tax Deductions That Shrink Your Bracket
Certain contributions come out before federal income tax is calculated, which directly lowers your taxable income:
- Traditional 401(k): up to $23,500 in 2025 ($31,000 if age 50+)
- Traditional IRA: up to $7,000 ($8,000 if age 50+), income limits apply for deduction
- HSA: up to $4,300 single / $8,550 family if on a qualified HDHP
- FSA, transit, and dependent-care accounts: smaller but real
Our single filer earning $85,000 who contributes $10,000 to a traditional 401(k) now has taxable income of $60,000 instead of $70,000. The $10,000 contribution saves $2,200 in federal tax (since it came off the 22% bracket), meaning the true cost of that $10,000 contribution was $7,800. Our Retirement 401(k) Calculator shows how this compounds over decades.
Note: Roth contributions do not reduce current taxable income, but qualified withdrawals in retirement are tax-free. Deciding between Traditional and Roth is largely a bet on whether your tax rate in retirement will be higher or lower than today.
Frequently Asked Questions
Is it ever bad to get a raise?
For income tax purposes, no. You always keep more money after a raise, just not the full dollar. Edge cases exist around means-tested benefits (ACA subsidies, student aid, certain credits) where a small raise can trigger a cliff. Those are benefit cliffs, not tax cliffs.
Why is my tax refund smaller this year even though I made the same amount?
Refunds reflect how accurately your withholding matched your actual tax. A smaller refund often means you had better withholding, not higher tax. Compare total federal tax paid, not refund size.
Why does my paycheck show so much tax withheld?
Withholding tables assume your paycheck extrapolated over 12 months is your full annual income. If you get a bonus or lumpy income, withholding often overshoots. The annual reconciliation at tax time trues it up.
Does contributing to a 401(k) reduce my taxes dollar for dollar?
A $1,000 traditional 401(k) contribution reduces your taxable income by $1,000, which saves you $1,000 times your marginal rate. At the 22% bracket that is $220 in federal tax savings, not $1,000.
Estimate Your Actual Tax Bill
Rules of thumb are useful for understanding, but your situation has specific numbers. Use our Income Tax Calculator to enter your filing status, state, gross income, pre-tax deductions, and see federal + state + FICA combined, along with both your marginal and effective rates. Once you can see those two numbers clearly, most financial decisions (401(k) contributions, side income, state relocations) get much easier to reason about.