Understand

Guides and resources

In-depth guides that sit alongside each tool, plus our methodology, sources and editorial standards.

Guides and methodology

Our 8-step method, with a worked example and the comparison tool.

Hours, miles and money — with Census and IRS reference figures.

Tax owed vs tax withheld, 2026 brackets, FICA and the W-4.

The rules and checks behind every tool on this site.

How we import and show BLS wage data.

How guides are researched, sourced and updated.

2026 data for five retiree households in every state, with a CSV.

Free embeddable paycheck and state tax calculators, with copy-and-paste code.