Sources

This site is an independent informational tool. It links to official resources so you can verify details (especially where state rules differ).

IRS tools used across the site

• IRS — Tax Withholding Estimator (official paycheck withholding tool)
• IRS — About Form W‑4 (official form overview)

State tax agency links

Each state calculator page includes official links for that state (and a fallback to the agency homepage when available). Those links are provided for verification of residency, withholding, and filing guidance. Because state sites can reorganize URLs, the Official state tax pointers block is designed to help you find the right official section quickly.

Review & updates

• Model assumptions are documented on Methodology.
• Editorial rules (sources, corrections, monetization) are listed on Editorial policy.
• Last reviewed date is shown in the footer across pages (current site review: 2026-01-12).

If you notice an official link that changed or a page that should be updated, please use the Contact page.