Editorial policy

Who writes the content

All calculators, explanatory articles and blog posts on apputil.com are written and reviewed by Rodrigo Brito, the site editor. Where a topic touches health, finance or safety, published guidance from recognised bodies is used as the reference and named in the text so readers can follow it back to the source.

We do not publish guest posts, syndicated filler or bulk machine-generated text. Every page exists because a specific calculation was worth explaining.

How a tool gets published

• A calculation is chosen because readers search for it and the existing answers are poor or hidden behind ads.
• The formula is sourced from a documented standard or peer-reviewed reference and implemented in code.
• Results are validated against an independent implementation — a spreadsheet, an official table, or a published worked example.
• An explanatory article is written: what the formula means, how to read the result, where it stops being reliable.
• Frequently asked questions are added from real search queries, so the page answers the follow-up question too.
• The page is reviewed for clarity and accessibility, then published in all three languages.

Sources

Health tools follow the definitions used by the World Health Organization and the equations published in peer-reviewed nutrition and sports-science literature, such as Mifflin-St Jeor for resting metabolism and the Jackson-Pollock skinfold equations for body fat.

Unit conversion follows the SI definitions maintained by the BIPM and the exact conversion factors defined by NIST. Financial tools follow standard actuarial formulas — the same ones used by spreadsheet functions such as PMT and FV.

Accuracy, limits and disclaimers

Calculators are informational tools, not professional advice. A BMI figure is a screening indicator, not a diagnosis; a loan simulation is an estimate that excludes the fees and taxes specific to your contract; a calorie target is a starting point that needs adjusting to how your body actually responds.

Where a method has known limitations, the page states them. We would rather lose a click than give a confident answer that is wrong for the person reading it.

Corrections

If you find an error, write to [email protected] with the inputs you used and the result you expected. Confirmed errors in a formula are fixed as a priority, and the page carries an updated date so you can see when it last changed.

Advertising and independence

The site is funded by display advertising served by third-party networks. Advertisers do not review content before publication and have no influence over which tools are built or what the articles conclude. Advertising units are visually separated from editorial content and never disguised as calculator results or article text.

We publish no sponsored posts and no paid links. If that ever changes, any commercial relationship will be disclosed at the top of the page it affects.