About this site

NetWorthMath is an independent, individually run collection of personal-finance calculators: take-home pay for all 50 states and DC, bonus and RSU withholding, 401(k) growth, capital gains, and credit card points valuations, plus plain-English guides to the rules behind them. It is not affiliated with, endorsed by, or sponsored by any bank, card issuer, airline, or government agency.

Where the numbers come from

The site has one editorial rule above all others: no figure is ever estimated from memory. Every tax parameter — federal brackets, standard deductions, FICA rates and wage bases, state brackets and supplemental withholding rates — is transcribed from a primary source: IRS revenue procedures and publications, and each state revenue agency's own withholding tables. Points and miles valuations distinguish program-defined rates (facts, taken from the program) from editorial estimates (drawn conservatively from the major published valuation surveys). The source URLs are recorded alongside every value in the site's data files, and each page shows when its figures were last verified.

How the calculators are built and tested

All calculator math runs in your browser — nothing you type is sent to us or stored. The same tax code that renders the numbers on each page is covered by an automated test suite whose expected values were computed by hand from the underlying brackets, not copied from the code's own output, so a math error cannot silently ship. Each calculator page carries an "About this estimate" section stating exactly what is modeled, what is simplified, and what is left out.

Update cadence

Tax figures are refreshed for each new tax year when the IRS and state agencies publish their inflation adjustments (the current figures are for 2026), and corrected mid-year if a law changes a rate retroactively. Points valuations are re-checked against their sources on a roughly monthly cycle and after major program news. Pages display the date their numbers were last verified.

Corrections

If a number here disagrees with a primary source, the source is right and we want to know. Email [email protected] with a link to the source; correction reports are prioritized over everything else.

How this site makes money

Some links on this site are affiliate links, and we may also show ads. Advertiser disclosure: some links on this site are affiliate links, meaning we may earn a commission if you apply for a product through them, at no extra cost to you. This compensation does not influence our valuations or calculator results. Opinions expressed here are the author's alone and have not been reviewed, approved, or endorsed by any card issuer or airline. Advertising never influences a valuation or a tax figure — the numbers come from the sources above, full stop.

Contact

Questions or corrections: [email protected]. More detail is on the contact page.