Do Your Own Math exists because most product-advice sites are shopping lists wearing a lab coat. We build the opposite: calculators that show their working — the assumptions, the sources, and the number you actually asked for. On this site, "you don't need to buy anything" is always an allowed answer, and several of our tools reach it regularly.
DYOM is run by an independent analyst, working under the site's name rather than a personal byline, with modern research tools (including AI) doing the heavy lifting on literature search and arithmetic — and every output checked against the sources before it is published.
We know a faceless site has to earn trust the hard way. So we don't ask you to trust us; we ask you to check us. Every claim links to its source, every calculator exposes its assumptions as sliders you can change, and our corrections page lists what we got wrong, in public, including the recommendations we withdrew.
We are desk researchers. We have not physically tested the products we point to. We work from independent certifications (NSF/ANSI, AHAM, IAPMO), manufacturer specifications, published lab-style reviews and peer-reviewed literature — and we link them so you can verify. If you want hands-on teardown reviews, read a site that does those, and then come back for the math.
Nothing here is medical, legal or financial advice; it is general information and planning arithmetic.
Some outbound links are affiliate links, always declared. The commission never decides what a calculator says — that separation is a build rule of the site, not a promise. The full explanation lives on how we make money.
Our editorial rules — evidence grading, mandatory contradiction disclosure, adversarial audits that cannot be silently ignored — are described on the methodology page. They are also enforced mechanically: a page that cites a stale or unsupported claim fails our build and cannot be published.
Spotted an error? We would honestly rather know. Every page tells you when it was last reviewed.