A paycheck withholds money in three separate buckets, and only the first one is a flat rate: FICA at 7.65% (6.2% Social Security + 1.45% Medicare), federal income tax driven by your Form W-4, and state income tax if your state charges one. For a $52,000 salary paid weekly — $1,000 a week, single, standard W-4, no state wage tax — a 2026 paycheck withholds $78.08 of federal income tax, $62.00 of Social Security and $14.50 of Medicare: $154.58 in total, or 15.5% of gross, leaving $845.42 net. Earn more and the percentage climbs, because only FICA is flat — 14.2% at $40,000, 18.3% at a $78,000 salary, 24.1% at $150,000.
The lines that come out of every paycheck
| Withholding line | 2026 rate or limit | Who sets it |
|---|---|---|
| Social Security (OASDI) | 6.2% of wages, first $184,500 only | Statute — IRS Topic 751 |
| Medicare (HI) | 1.45% of all wages, no cap | Statute — IRS Topic 751 |
| Additional Medicare | +0.9% above $200,000 of wages | IRS Topic 751 |
| Federal income tax | 10% to 37%, on taxable wages | IRS Pub. 15-T + your W-4 |
| State income tax | Varies — $0 in states with no wage tax | Your state’s tables |
FICA is not negotiable: it is a percentage of gross wages, identical for a $30,000 salary and a $300,000 one, and there is no form you can file to change it. Everything else on that list is either elective (pre-tax benefits) or adjustable (income tax withholding).
FICA: the 7.65% that never changes
Two lines make up FICA, and only one of them has a ceiling.
- Social Security — 6.2%, capped. The Social Security Administration sets an annual contribution and benefit base: $184,500 for 2026. Wages above that are not subject to the 6.2%. The most an employee can contribute in 2026 is $11,439, and the employer matches it.
- Medicare — 1.45%, uncapped. Every dollar of covered wages is subject to it, all year, no matter how much you earn.
- Additional Medicare — 0.9%. Employers must withhold this once wages paid in a calendar year exceed $200,000, without regard to filing status. Two earners in one household can each stay under $200,000 at work and still owe the tax between them when they file.
Practical consequence: a $180,000 salary and a $250,000 salary both pay 6.2% on the first $184,500, but the $250,000 earner’s Social Security line stops partway through the year and their take-home jumps. On a biweekly payroll, that switch happens while the YTD column is at $184,500 — a legitimate change, not a payroll error.
Federal income tax: how the IRS computes your withholding
Federal income tax is the line nobody can reproduce from a rate sheet, because it is progressive and it depends on the W-4 you filed. Pub. 15-T, the IRS’s federal income tax withholding methods for 2026, defines the arithmetic employers use — the percentage method:
- Annualize the pay period: weekly × 52, biweekly × 26, semi-monthly × 24, monthly × 12.
- Subtract the standard deduction for your filing status: $16,100 for single or married filing separately, $32,200 for married filing jointly, $24,150 for head of household in 2026.
- Apply the 2026 brackets to what is left.
- Divide by the number of pay periods to get the amount that comes out of this paycheck.
| Taxable income (2026) | Single | Married filing jointly |
|---|---|---|
| 10% | up to $12,400 | up to $24,800 |
| 12% | $12,400 – $50,400 | $24,800 – $100,800 |
| 22% | $50,400 – $105,700 | $100,800 – $211,400 |
| 24% | $105,700 – $201,775 | $211,400 – $403,550 |
| 32% | $201,775 – $256,225 | $403,550 – $512,450 |
| 35% | $256,225 – $640,600 | $512,450 – $768,700 |
| 37% | over $640,600 | over $768,700 |
Those thresholds are the tax year 2026 inflation adjustments, which is why a raise does not push your whole salary into a higher rate. Only the dollars above a threshold are taxed at the higher rate.
Worked example: $52,000 a year, paid weekly
| Stub line | Per week | Per year |
|---|---|---|
| Gross wages | $1,000.00 | $52,000 |
| Federal income tax | −$78.08 | −$4,060 |
| Social Security (6.2%) | −$62.00 | −$3,224 |
| Medicare (1.45%) | −$14.50 | −$754 |
| Net pay | $845.42 | $43,962 |
The federal line breaks down like this: annualize ($52,000), subtract the single standard deduction ($52,000 − $16,100 = $35,900 taxable), then apply the brackets — 10% on the first $12,400 ($1,240) plus 12% on the next $23,500 ($2,820) = $4,060 for the year, or $78.08 a week. Total withholding is $154.58 of a $1,000 check.
How much is withheld at different salaries
Single filer, standard W-4, no pre-tax deductions, no state income tax:
| Annual salary | Federal income tax | Social Security | Medicare | Total withheld | % of gross |
|---|---|---|---|---|---|
| $40,000 | $2,620 | $2,480 | $580 | $5,680 | 14.2% |
| $52,000 | $4,060 | $3,224 | $754 | $8,038 | 15.5% |
| $78,000 | $8,330 | $4,836 | $1,131 | $14,297 | 18.3% |
| $100,000 | $13,170 | $6,200 | $1,450 | $20,820 | 20.8% |
| $150,000 | $24,734 | $9,300 | $2,175 | $36,209 | 24.1% |
The trend is the answer to the question behind the question: withholding is not one percentage, it is a flat 7.65% plus a progressive layer that grows with income. Jumping from $52,000 to $78,000 raises gross pay by 50% but total withholding by 78% — the second salary puts part of your income in the 22% bracket.
The percentage holds steady, the amounts move with pay frequency
Same $52,000 salary, same single filer. Only the size of each check changes:
| Pay frequency | Gross per period | Federal income tax | FICA | Total withheld | Net pay |
|---|---|---|---|---|---|
| Weekly (52) | $1,000.00 | $78.08 | $76.50 | $154.58 | $845.42 |
| Biweekly (26) | $2,000.00 | $156.15 | $153.00 | $309.15 | $1,690.85 |
| Semi-monthly (24) | $2,166.67 | $169.17 | $165.75 | $334.92 | $1,831.75 |
| Monthly (12) | $4,333.33 | $338.33 | $331.50 | $669.83 | $3,663.50 |
Every row withholds 15.5% of gross. Frequency changes cash flow, not the annual total — which is why a semi-monthly check with a slightly different deposit amount is normal and not a raise or a cut.
Filing status and pre-tax deductions change the federal line
| Scenario ($78,000 salary) | Federal income tax | Total withheld | % of gross |
|---|---|---|---|
| Single, standard W-4 | $8,330 | $14,297 | 18.3% |
| Married filing jointly, standard W-4 | $5,000 | $10,967 | 14.1% |
| Single, with a 5% pre-tax 401(k) | $7,472 | $13,141 | 16.8% |
Filing status is worth $3,330 a year here, because the married standard deduction is $32,200 instead of $16,100 and the brackets are twice as wide.
Pre-tax deductions work on the withholding side: a 5% traditional 401(k) contribution removes $3,900 from taxable wages at this salary, which cuts federal income tax by $858 — exactly 22% of the contribution, your marginal rate, or about $16.50 a week. FICA is figured on the post-deduction wages too, so Social Security and Medicare fall by another $299 a year. That is why two coworkers with identical salaries can have very different withholding: one contributes to a 401(k), an HSA or a dependent care FSA and the other does not.
What withholding is not
Withholding is a running prepayment of your income tax, not a final bill. You reconcile it once a year on your return: withhold too much and the excess comes back as a refund; withhold too little and you owe the difference, plus possible underpayment interest. The only portion that never comes back is FICA, which is your contribution to Social Security and Medicare. If your refund was large last year, the fix is a new W-4 — Step 4(b) for deductions, Step 3 for dependents, Step 4(c) for a flat extra amount per period — not a change to your FICA.
Run your own numbers instead of estimating by hand: the federal paycheck calculator applies FICA and the 2026 percentage method to any pay frequency, and these add the state line: California, New York, Texas and Washington — the last two with zero state withholding.