Guides

Plain-English explainers on how paycheck withholding actually works, sourced the same way every calculator on this site is.

• What Is FICA?Social Security and Medicare tax explained — rates, wage base, and the self-employment version.
• How the W-4 WorksA walkthrough of Steps 1-4, and why two people with the same salary get different withholding.
• Why Is My Bonus Taxed at 22%?The IRS flat-rate rule, the aggregate method, and why 22% isn't your real tax rate.
• California Paycheck GuideMethod B withholding, uncapped SDI, and the HSA add-back most calculators miss.