Every paycheck has three layers of federal tax: income tax withholding plus the two FICA taxes. Here’s what comes out and why.

The three withholdings

  1. Federal income tax — based on your W-4 and the tables in IRS Pub. 15-T (percent method).
  2. Social Security — 6.2% up to the $184,500 wage base (2026).
  3. Medicare — 1.45% (plus 0.9% surtax on earnings above $200,000).

Example: a $1,500 paycheck

With a standard W-4, the validated example from IRS Pub. 15-T nets:

  • Gross: $1,500.00
  • Federal withholding + FICA: $274.94
  • Net pay: $1,225.06

The paycheck withholding calculator shows your exact breakdown.

Withholding vs. your tax bill

Withholding is just a prepayment. If your W-4 is accurate, you end the year near zero: over-withholding means a refund, under-withholding means you owe. If you have freelance income, the estimated tax calculator keeps you covered, and the self-employment tax calculator handles the SE side.