Payroll Tax Calculator
Simplified US federal FICA calculation only (Social Security + Medicare). Does not include federal/state income tax withholding or state-specific payroll taxes.
What FICA Actually Takes Out of Each Paycheck
Every paycheck in the US carries two federal payroll taxes that fund Social Security and Medicare, collectively known as FICA. Social Security tax stops once an employee's year-to-date wages cross a fixed annual cap, while Medicare tax never stops — and above a certain income threshold, an additional Medicare surtax kicks in on top of the standard rate. Getting the sequencing right, especially around the Social Security wage base, is where manual payroll calculations most often go wrong.
The Formula
Medicare Tax = Gross Pay × 1.45%
Additional Medicare Tax = Wages Over Threshold (YTD basis) × 0.9%
This calculator computes a simplified US federal FICA figure only — it does not include federal or state income tax withholding, or state-specific payroll taxes. The Social Security wage base defaults to $168,600 and the Additional Medicare threshold defaults to $200,000, both of which can be overridden for a different tax year or filing status.
Worked Examples
| Scenario | Gross Pay | YTD Wages Before | Social Security Tax | Medicare Tax | Total FICA |
|---|---|---|---|---|---|
| Mid-year, well under wage base | $3,500.00 | $50,000.00 | $217.00 | $50.75 | $267.75 |
| Near the wage base cap | $10,000.00 | $165,000.00 | $223.20 (only $3,600 taxable) | $145.00 | $368.20 |
In the second scenario, only $3,600 of the $10,000 gross pay is subject to Social Security tax because year-to-date wages plus this period's pay would otherwise exceed the $168,600 wage base.
Where This Calculation Matters
- Running payroll accurately — small businesses processing payroll without dedicated software still need to withhold FICA correctly every pay period.
- Wage base tracking — once an employee's year-to-date wages cross the Social Security wage base, withholding for that tax stops entirely for the rest of the year, which requires tracking cumulative wages, not just the current paycheck.
- High earners and the additional Medicare surtax — employees crossing the Additional Medicare threshold mid-year need the surtax applied only to wages above that point, not the full paycheck.
- Budgeting employer costs — employers match the Social Security and standard Medicare portions (though not the Additional Medicare surtax), so this figure is also a starting point for estimating total payroll tax burden.
How to Use This Calculator
- Enter Gross Pay This Period.
- Optionally enter YTD Wages Before This Period (defaults to 0 if left blank).
- Optionally override the Social Security Wage Base (defaults to $168,600).
- Optionally override the Additional Medicare Threshold (defaults to $200,000).
- Select Calculate to see the total FICA tax along with the Social Security, Medicare, and Additional Medicare breakdown.
Related Calculations
Compare this against the Sales Tax Calculator for a different tax scenario, or check whether the resulting payroll entries keep your books balanced with the General Ledger Balance Calculator.