Editorial Policy

Our Content Standards

HealthCalc is an independent educational project that publishes free health calculators and plain-language articles. Our goal is to make standard health formulas understandable and usable, while being clear about what those formulas can and cannot tell you.

This page explains how content is created, which sources we rely on, how we handle errors, and how advertising is kept separate from editorial decisions. It applies to every calculator, article, and explanatory page on healthcalc.online.

Who produces this content

HealthCalc is written and maintained by an independent developer, not by a clinic or medical practice. The site does not employ physicians, dietitians, or other licensed clinicians, and nothing on the site is a substitute for individualized medical advice.

Because the site is run by one person, every page is reviewed by the same maintainer. All substantive changes are recorded in the page's structured data and the Methodology & Sources page. Questions, corrections, and source suggestions can be sent through the Contact page or by email to goatabdullahmoideen@gmail.com.

How calculators are researched and built

1. Choose a standard, published method. We prefer equations and classifications that appear in clinical guidelines or peer-reviewed literature — for example, the Mifflin-St Jeor equation for basal metabolic rate, WHO BMI categories, the US Navy circumference method for body fat, and the Karvonen formula for heart-rate training zones.
2. Read the primary source. Before implementing a formula, we check the original publication or the authoritative guideline (WHO, NIH, CDC, National Academies, or the relevant clinical body) rather than relying on secondary summaries.
3. Implement exactly what the source specifies. Units, constants, rounding, and population assumptions are transcribed from the source. Where a calculator uses a widely accepted simplification, the limitation is stated on the page.
4. Test with known examples. Each calculator is exercised with hand-calculated reference values, metric and imperial inputs, boundary values, and invalid input. Results are checked against independent calculators or worked examples where available.
5. Label estimates honestly. Every calculator states that its output is an estimate for informational purposes, not a diagnosis. Pages include common limitations, such as BMI's inability to distinguish muscle from fat.

Formulas, constants, and citations for each tool are listed on the Methodology & Sources page.

AI-assistance disclosure

In the interest of transparency: drafts of some calculator pages and articles were produced with the help of AI writing and coding tools. AI output is treated as a draft, not a source. Formulas and factual claims are checked against the published references cited on the Methodology & Sources page before publication, and calculator behavior is tested manually in a browser.

AI tools are never used to generate individualized medical advice, to invent citations, or to fabricate author credentials. If you believe a page contains an error or an unsupported claim, please report it through the Contact page so it can be corrected.

Sources we rely on

Depending on the topic, primary references include:

• World Health Organization (WHO) guidance and indicator definitions
• US National Institutes of Health (NIH), CDC, and National Academies reports, including the Dietary Reference Intakes
• Peer-reviewed journal articles, cited with DOI or PubMed identifiers wherever available
• Clinical guidelines from bodies such as the American Heart Association and the American College of Sports Medicine
• Original publications for named formulas (for example, Mifflin & St Jeor, 1990; Karvonen et al., 1957)

We do not cite content farms, unattributed blog posts, or AI-generated summaries as sources. When a source is unavailable or a formula is contested, we say so on the page instead of presenting the result as settled science.

Accuracy, corrections, and updates

Health and nutrition guidance changes. We review calculator pages periodically and update them when a guideline changes, a formula is superseded, or a reader reports a problem.

• Reporting an error: email goatabdullahmoideen@gmail.com or use the Contact page. Please include the page URL and, if possible, the source that supports the correction.
• What happens next: reports are reviewed against the cited source. Confirmed factual or calculation errors are corrected and the page's dateModified value is updated. If a claim cannot be supported, it is removed.
• Target turnaround: we aim to acknowledge correction requests within 7 days and to publish confirmed corrections within 30 days.

Advertising and independence

HealthCalc is free to use and is supported by advertising served through Google AdSense. Advertising is clearly distinguishable from editorial content. Advertisers do not review, approve, or influence calculator formulas, articles, rankings, or recommendations, and we do not publish sponsored calculators or paid product placements.

We do not sell user health data. Calculations run in your browser; the values you enter are not sent to our servers. See the Privacy Policy for details on analytics, consent, and advertising cookies.

Medical disclaimer

Content on HealthCalc is for general information and education only. It is not medical advice, diagnosis, or treatment, and it does not create a clinician-patient relationship. Individual circumstances — age, pregnancy, medication, chronic disease, disability, and more — can change what is appropriate for you. Always consult a qualified healthcare professional before making decisions about your health, diet, exercise, or treatment, and never delay seeking professional advice because of something you read here.

If you think you may have a medical emergency, call your local emergency number immediately.

Related pages

• Methodology & Sources — formulas and citations for every calculator
• About HealthCalc — who runs the site and why it exists
• How It Works — what each tool does and how to read its results
• Privacy Policy — data handling and advertising
• Contact — corrections, questions, and feedback