Payroll Tax Calculator: Estimate FICA, Medicare & Withholding

The Problem Most Employees Don't Know They Have

When a job posting says "$75,000 salary," most applicants mentally adjust for income taxes. Far fewer account for payroll taxes — yet those costs are unavoidable and substantial. For the same $75,000 salary, an employee pays $4,650 in Social Security tax and $1,088 in Medicare tax in 2026, totaling $5,738 in FICA. Their employer pays an identical $5,738 on top — bringing the total payroll tax cost of that $75,000 salary to $11,476.

This matters when comparing a W-2 job to a freelance contract or business ownership. A $75,000 W-2 salary and a $75,000 1099 contract are not equivalent. The contract worker pays the full 15.3% self-employment tax themselves (on ~92.35% of net income, per IRS Publication 334) — though half is deductible. The IRS collected approximately $1.24 trillion in payroll taxes in fiscal year 2025, per the Congressional Budget Office — making it the second-largest federal revenue source after income taxes.

Understanding payroll taxes also matters for withholding accuracy. The IRS's own data shows that approximately 30 million taxpayers owed additional tax at filing in a recent year — many of them because of underwithholding on side income, a second job, or a new W-4 that wasn't filled out correctly. The income tax calculator can help you model your full-year liability and whether your withholding is on track.

FICA Taxes Explained: Social Security and Medicare

FICA stands for the Federal Insurance Contributions Act, enacted in 1935 as part of the Social Security Act. It funds two programs: Social Security (Old Age, Survivors, and Disability Insurance — OASDI) and Medicare (Hospital Insurance — HI). According to IRS Topic 751, the 2026 rates are:

Source: IRS Topic 751 (Social Security and Medicare Withholding Rates); SSA Contribution and Benefit Base, 2026. The $176,100 Social Security wage base is set annually by the Social Security Administration.

The 2026 Social Security Wage Base: $176,100

The Social Security wage base increased from $176,100 in 2025 to $176,100 in 2026 — a $8,400 jump. According to the Social Security Administration, the wage base is adjusted annually based on national average wage indexing. This means higher earners will pay Social Security tax on more of their income year over year.

Once an employee's wages reach $176,100 for the calendar year, Social Security withholding stops. For the rest of the year, only Medicare (1.45%) and any applicable Additional Medicare Tax continue to be withheld. If you work multiple jobs and your combined wages from all employers exceed $176,100, you may overpay Social Security tax during the year — the excess is refunded as a credit on your Form 1040 (Line 11 of Schedule 3).

Employers, however, cannot see combined wages from multiple employers. Each employer withholds Social Security tax on the wages it pays until that employer's wages reach $176,100 — even if the employee has already hit the limit at a different job. The employee claims the excess as a credit at filing; the employer does not get a refund.

The Additional Medicare Tax: Who It Hits and When

The Additional Medicare Tax (enacted under the Affordable Care Act, effective 2013) imposes an extra 0.9% Medicare tax on wages and self-employment income above specific thresholds. Per IRS Publication 926 and Form 8959 instructions:

• Single / Head of Household / Qualifying Widow(er): $200,000
• Married Filing Jointly: $250,000
• Married Filing Separately: $125,000

Employers withhold the 0.9% surtax once any single employee's wages cross $200,000 in the calendar year — regardless of that employee's filing status. A married employee earning $180,000 whose spouse earns $100,000 has combined household wages of $280,000, which exceeds the $250,000 MFJ threshold. But the employer withholds nothing extra because no individual wage stream exceeds $200,000. The couple owes the 0.9% on $30,000 — $270 — and may face an underpayment if they don't adjust withholding or make estimated tax payments.

Unlike the base Medicare tax, the employer does not match the Additional Medicare Tax. It is solely an employee (and self-employed person) obligation.

Full Worked Example: $75,000 Salary, 2026

Let's walk through the complete payroll tax calculation for a single filer earning $75,000 annual salary, claiming the standard W-4 (single, no dependents, no additional withholding), paid semi-monthly (24 pay periods).

Federal income tax estimate uses 2026 brackets (projected) and the standard deduction of $15,750 for single filers. Actual withholding depends on W-4 elections. State income taxes not included.

High-Income Scenario: $250,000 Salary with Additional Medicare Tax

Once wages exceed $176,100, the Social Security calculation changes. Here's the payroll tax math for a single filer earning $250,000:

Source: IRS Topic 751; IRS Publication 15 (Employer's Tax Guide), 2026 edition. The employer does not match the 0.9% Additional Medicare Tax.

Federal Income Tax Withholding: How Your W-4 Drives the Number

FICA taxes are fixed by law — the rate is the same for everyone regardless of their elections. Federal income tax withholding, however, is highly variable depending on your Form W-4 elections, your pay frequency, and your annual wage level.

The IRS redesigned Form W-4 in 2020 to move away from the old "allowance" system. The current W-4 has five steps:

1. Step 1: Personal Information. Filing status (Single/MFS, MFJ, or Head of Household). This is the single most important input — it determines your withholding bracket and standard deduction treatment.
2. Step 2: Multiple Jobs or Spouse Works. If you have multiple jobs simultaneously, or if you're married and both spouses work, you should complete this step. Failing to do so is a leading cause of underwithholding.
3. Step 3: Claim Dependents. Enter the Child Tax Credit amount and other dependent credits here. The 2026 Child Tax Credit is $2,000 per qualifying child under 17. Claiming the credit reduces withholding — accurately, if the credit will be on your return.
4. Step 4: Other Adjustments. For other income (interest, dividends, freelance income) not subject to withholding (Step 4a), deductions if you plan to itemize above the standard deduction (Step 4b), or any extra withholding amount per pay period (Step 4c).
5. Step 5: Sign and date.

Per IRS Publication 15-T, employers use either the Wage Bracket Method (table lookup by pay period and filing status) or the Percentage Method (math-based, required for complex W-4s) to compute withholding. Most payroll software uses the Percentage Method. The goal is for withholding to closely approximate the employee's final tax liability, though it is not required to be exact.

Use the tax refund calculator to project whether you'll owe money or receive a refund based on your current withholding and estimated income.

Employer Payroll Tax Obligations: Form 941, Deposits, and FUTA

If you employ workers, your payroll tax obligations go well beyond calculating the withholding. You must also:

Form 941: Quarterly Federal Tax Return

Per IRS Form 941 instructions (March 2026 revision), employers file Form 941 to report: (1) wages paid to employees, (2) tips employees reported, (3) federal income tax withheld, (4) both employer and employee share of Social Security and Medicare taxes, and (5) Additional Medicare Tax withheld.

Filing deadlines:

• Q1 (Jan–Mar): Due April 30, 2026
• Q2 (Apr–Jun): Due July 31, 2026
• Q3 (Jul–Sep): Due October 31, 2026
• Q4 (Oct–Dec): Due January 31, 2027

Employers who deposited all payroll taxes on time and in full receive an automatic 10-day extension to file the return itself — but only the paperwork, not the deposits.

Deposit Schedules: Monthly vs. Semi-Weekly

The timing of tax deposits depends on your "lookback period" — the 12-month period ending June 30 of the prior year. Per IRS Publication 15 (Circular E), 2026 edition:

• Monthly depositor: If you reported $50,000 or less in payroll taxes during the lookback period. Deposits due by the 15th of the month following the payroll month.
• Semi-weekly depositor: If you reported more than $50,000. Deposits due Wednesday for payrolls on Saturday–Tuesday; due Friday for payrolls on Wednesday–Friday.
• $100,000 next-day rule: If your accumulated tax liability in any single day exceeds $100,000, you must deposit by the next business day — regardless of your normal deposit schedule.
• New employers: Automatically monthly depositors until the lookback period establishes otherwise.

FUTA: Federal Unemployment Tax

The Federal Unemployment Tax Act (FUTA) is a separate payroll tax paid only by employers — employees do not pay FUTA. The 2026 FUTA rate is 6.0% on the first $7,000 of wages paid to each employee annually. However, employers who pay state unemployment taxes on time receive a credit of up to 5.4%, reducing the effective FUTA rate to 0.6% — a maximum of $42 per employee per year.

FUTA is deposited quarterly when the liability reaches $500. Employers with annual FUTA liability under $500 can carry forward and pay with the annual Form 940 (due January 31). FUTA and the state unemployment insurance system together fund unemployment benefit payments to laid-off workers.

Self-Employment Tax: The Freelancer's Full Payroll Tax Burden

Self-employed individuals — sole proprietors, single-member LLCs, independent contractors, and partners in partnerships — pay self-employment (SE) tax instead of payroll taxes. The SE tax rate is 15.3% on net self-employment income up to the Social Security wage base ($176,100), then 2.9% above that (Medicare only, with the 0.9% Additional Medicare Tax applying above the same income thresholds as for employees).

One nuance: SE tax applies to 92.35% of net self-employment income, not 100%. This is because employees effectively reduce their Social Security wage base by the employer's share — the SE tax code replicates this by having self-employed people calculate SE tax on a slightly reduced base. Per Schedule SE instructions:

1. Calculate net self-employment income (Schedule C profit, less deductible business expenses)
2. Multiply by 92.35% (0.9235) — this is your "SE income subject to tax"
3. Apply 15.3% on the amount up to $176,100; 2.9% above (plus 0.9% over $200K)
4. Deduct half the resulting SE tax from your gross income on Form 1040 Schedule 1, Line 15

For a freelancer with $80,000 in net self-employment income: $80,000 × 0.9235 = $73,880 × 15.3% = $11,304 SE tax. Half of that ($5,652) is deductible from AGI — reducing the income tax bill as well as the SE tax base. For more detail on how this integrates with quarterly payments and deductions, see our self-employment tax guide.

Payroll Tax Rates Compared to Freelance: The Real Cost Difference

SE tax calculated on 92.35% of net income per Schedule SE. Freelancer figures assume $75K gross with minimal business expenses for simplicity. Tax savings from SE deduction estimated at 22% bracket.

This comparison illustrates why a $75,000 freelance contract is not equivalent to a $75,000 salary — the freelancer pays approximately $3,636 more in payroll-equivalent taxes (net of the deduction benefit), in addition to having no employer match for benefits like health insurance or 401(k). A fair freelance rate needs to account for these costs explicitly.

If you're a freelancer, use the quarterly estimated taxes guide to avoid underpayment penalties on your SE tax and federal income tax.

State Payroll Taxes: What Employers Also Owe

Federal payroll taxes are only part of the employer's payroll obligation. Most states impose:

• State Income Tax Withholding: Required in the 41 states that levy income taxes. Rates and withholding tables vary by state. Employers must register with the state revenue department and file state payroll tax returns (often quarterly, matching Form 941's schedule).
• State Unemployment Insurance (SUI/SUTA): All 50 states levy state unemployment insurance taxes, paid only by employers. New employer rates typically run 2–4%, applied to a state-defined wage base that varies from $7,000 (some states use the FUTA base) to $62,500 (Washington state). Experienced employers' rates adjust based on their unemployment claims history.
• State Disability Insurance (SDI): California, New York, New Jersey, Hawaii, and Rhode Island mandate employee and/or employer contributions to state short-term disability programs. California's SDI employee rate for 2026 is 1.1% on all wages with no wage cap (expanded from a prior cap under legislation effective 2024).

Common Payroll Tax Mistakes — and the Penalties

The IRS takes payroll tax compliance seriously. Payroll taxes represent collected trust fund money — amounts withheld from employees' paychecks that the employer holds in trust for the government. Misusing these funds or failing to deposit them triggers severe penalties:

• Failure to deposit penalty (IRC §6656): 2% for deposits 1–5 days late; 5% for 6–15 days late; 10% for more than 15 days late; 15% if amount remains unpaid 10 days after an IRS notice. This applies to each missed deposit.
• Trust Fund Recovery Penalty (TFRP): The IRS can pursue 100% of the unpaid trust fund taxes personally against any "responsible person" — which includes business owners, officers, and even bookkeepers who had authority over payroll decisions. This pierces the corporate veil entirely.
• Failure to file Form 941: 5% of unpaid tax per month, up to 25%.
• Misclassifying employees as contractors: If the IRS reclassifies workers, the employer owes both the employee AND employer share of FICA for the entire misclassification period, plus interest and penalties. The IRS Voluntary Classification Settlement Program (VCSP) allows prospective reclassification at reduced penalty for qualifying employers.

Frequently Asked Questions