This page states the rules this site follows when it decides what to publish, where the numbers come from, who is allowed to change them, and what happens when one of them turns out to be wrong.
A page goes live only when it meets four conditions. Failing any one of them keeps it in draft, no matter how much traffic the topic might draw.
The process is deliberately repetitive. Parameters are collected from the issuing agency first. The calculation is then implemented twice, once in the JavaScript that ships to the browser and once in a separate reference implementation, and the two are compared across the default scenario and a set of edge cases: zero interest, a single payment, the top and bottom of each input range. A third check executes the page's own script and compares its output against the reference model. If the three disagree by a cent, nothing is published.
Drafting is assisted by software, including language models, and we would rather say that plainly than imply otherwise. The assistance is not the standard; the verification is. A language model can produce a fluent paragraph, but it cannot make a number correct, and an unverified figure that reads well is worse than no page at all. Every number in the prose is checked against the same verified run that produced the calculator's output, which is why a figure quoted in a paragraph matches the table beneath it.
Government figures name the agency and the document, such as an IRS Revenue Procedure or a Social Security Administration fact sheet. Published rates and averages name the organization that publishes them. We do not write "studies show" without saying which study. Where a figure is our own estimate rather than a published one, the page labels it as an estimate and shows how it was derived.
When a source is superseded, the page is updated rather than left in place with a stale citation. The methodology page lists which source group applies to which calculator family.
Tax parameters are refreshed when the IRS and the Social Security Administration publish the following year's figures, usually in the fall, and the site moves to the new tax year as a single coordinated update rather than page by page. Rate-based defaults are scheduled for re-check against their source each quarter. Every calculator carries a visible review date, so a reader can see how current the page is before relying on it. Pages that show the most visible drift when parameters move are reviewed first.
If a formula, a default, or a statutory figure is wrong, it gets fixed and the review date at the top of the page changes on the same day. Corrections are not made silently: a substantive change to a published result is noted in the page's own history or on the methodology page.
If a page is wrong in a way that cannot be repaired, it is removed rather than left online with a warning. Send a correction to [email protected] or use the contact page, and include the inputs you used. A report that reproduces a discrepancy gets a reply; if we are wrong, the fix is published and the person who found it is credited unless they prefer otherwise.
The site is free and has no paywall. Revenue comes from display advertising served by Google AdSense, and from nothing else. There are no affiliate links on this site, no paid placements, and no sponsored pages. No advertiser reviews, approves, or sees a page before it is published, and no calculator result is shaped by what might be advertised next to it.
Advertising is served by a third-party network and is not selected by us. If an ad appears next to a page and looks like an endorsement of that page's arithmetic, it is not one.
Every page on this site is published under one name. Yongwen Wu builds the models, checks the figures, and is the person responsible when something is wrong. The about page describes that background and states plainly what this site is not: it is not financial advice, and it is not written by a licensed advisor.
Questions about this policy, requests to reproduce a calculator's method, and error reports all go to the same place: [email protected], or the contact page. Related documents are the methodology page, the terms of use, and the privacy policy.