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2025 TAX YEAR

How Federal Income Tax Is Calculated

Enter your salary and filing status below to see the exact step-by-step breakdown — from gross income to your real effective tax rate.

Your Information

$
FICA & Medicare — Calculated on Gross Income
Unlike federal income tax, FICA taxes are applied to your gross wages — the standard deduction has no effect on them.
Social Security
6.2%
of gross wages, up to $176,100
Your tax
—
Applies to Gross wages
2025 wage cap $176,100
Max tax (employee) $10,918.20
Employer matches Yes — 6.2%
Above $176,100 Tax stops completely
Once your gross wages hit $176,100 for the year, Social Security tax stops for the remainder of the year — a significant benefit for higher earners. The cap resets every January 1.
Medicare
1.45%
of gross wages, no cap
Your tax
—
Applies to Gross wages
Wage cap None — every dollar taxed
Employer matches Yes — 1.45%
High earner surcharge +0.9% above threshold
Surcharge threshold $200k single / $250k MFJ
The extra 0.9% Additional Medicare Tax is not matched by your employer — it comes entirely from your paycheck. Above the threshold you pay 2.35% total instead of 1.45%.
Why does this matter?
Federal income tax rewards you for deductions — the standard deduction alone removes $15,000 (single) from your taxable income. But FICA doesn't care about deductions at all. On a $50,000 salary, you pay Social Security and Medicare on the full $50,000, while federal income tax only applies to $35,000. This is why your FICA taxes often feel higher relative to your income than your federal income tax rate suggests.
2025 Federal Tax Brackets — Reference
Showing brackets for your selected filing status. Toggle to compare how brackets differ across statuses.