About HealthCalcPro
HealthCalcPro builds rigorous, source-cited lifestyle calculators — and tells you exactly when to see a real clinician instead.
Free, private, peer-reviewed formulas. No medical advice, no marketing fluff, no paywalled basics.
100% FreeNo RegistrationPeer-Reviewed FormulasPrivacy-FirstAd-Light
Home / About
HealthCalcPro provides general information and lifestyle calculation tools for educational purposes only. Nothing on this site constitutes medical advice, diagnosis, or treatment. Full disclaimer →
Why HealthCalcPro exists
Most online lifestyle calculators fall into two camps. The first is ad-cluttered SEO farms that scrape Wikipedia and call it "expert." They give you a number, serve you six ads, and never explain where the formula came from or why it might not apply to you. The second is apps that lock the basics behind a subscription — as if knowing your estimated calorie needs should cost $9 a month.
HealthCalcPro is the third option: free, privacy-first, with every formula traced back to its peer-reviewed primary source and every result accompanied by a clear "this is not medical advice" reminder. We are a lifestyle tool platform — not a medical service, not a clinical authority — and we are transparent about that distinction on every page.
Evidence-based self-knowledge about your body should be a public utility. That is the entire premise of this site.
Who built this — and what he is not
HealthCalcPro is built and maintained by a named, reachable person — not an anonymous content farm.
İsmail Günaydın
Founder & Lead Developer
Istanbul, Turkey · Working globally
I am İsmail Günaydın, the developer behind HealthCalcPro. My background spans chemistry, philosophy, and computer programming. I have 20 years of retail sales experience and have been a self-taught web developer since 2020. I have worked in SEO, GEO, and digital marketing for 15+ years, published 11+ books on Amazon KDP, and operate a portfolio of 16 online tools and brands.
What I do is build calculators that faithfully implement formulas published in peer-reviewed research and recognized lifestyle guidelines — Mifflin-St Jeor, U.S. Navy Method, WHO BMI categories, USDA Dietary Guidelines — source every claim, and pair every result with a reminder that a real clinician should be consulted for personal medical decisions.
What I am not
I am not a physician, registered dietitian, certified trainer, or any kind of medical professional. I do not give medical advice, and HealthCalcPro is not a medical service. Every result page on this site carries a prominent disclaimer directing you to consult a qualified clinician for personal health decisions. This transparency is not a weakness — it is the point.
Background & focus areas
Chemistry & philosophy20 yrs retail salesSelf-taught developer (2020)15+ yrs SEO/GEO/AEO11+ books published16-site portfolioNext.js / ReactPrivacy-first design
Our editorial principles
These are not aspirational — they describe how every calculator on this site is built.
Primary sources only
Every formula traces to a peer-reviewed publication or recognized clinical guideline — WHO, CDC, NIH, USDA, ACSM — that we link to directly. We do not implement formulas sourced from blog posts or aggregator sites.
Population estimates, not medical advice
We provide population-average estimates with clear context about what they can and cannot tell you. We never give individual medical advice, and every result carries a "consult a clinician" reminder.
Your data stays in your browser
All calculations run in browser JavaScript. We do not see your inputs, store them on servers, or share them with third parties. The Health Dashboard saves results to browser localStorage only — nothing leaves your device.
Disclaimer on every result
The medical disclaimer is not a footer afterthought. It appears on every calculator result page, on this page, and in our editorial policy. It is repeated because it matters.
Honest about limitations
When the math is uncertain or a formula does not apply to a population — athletes, pregnant women, the elderly, children — we say so explicitly on the result page rather than pretending the number is universal.
A note on the “clinician-reviewed” phrase
We previously used the phrase “clinician-reviewed” in some of our marketing copy. To be fully accurate: what we actually do is implement formulas that have been peer-reviewed and clinically validated in the published research we cite (Mifflin-St Jeor, U.S. Navy Method, WHO BMI categories, ACSM guidelines, and others). We do not have named clinical professionals on staff who individually review each calculator.
We are updating our marketing language to remove the “clinician-reviewed” claim where it overstates what we provide. Our authority comes from the peer-reviewed sources we cite — not from clinical credentials we do not hold. We believe this transparency makes the site more trustworthy, not less.
For the full documentation of each calculator's formula source, see our Methodology page. For our editorial standards, see the Editorial Policy.
Who this site is — and is not — built for
Built for
- ✓Adults wanting to understand population-average lifestyle metrics — BMI, estimated calorie needs, body fat ranges, heart rate zones
- ✓Coaches and trainers wanting transparent calculator references to share with clients, with appropriate disclaimers already built in
- ✓Curious people who want to know how the number is computed, not just what the number is
- ✓Anyone who values free, source-cited tools without paywalls or required registration
Not built for
- ✗Diagnosing medical conditions — these are educational estimates, not diagnostic instruments
- ✗Replacing professional medical advice — always consult a qualified clinician for personal health decisions
- ✗Children under 18 — BMI and body composition categories for adults do not apply to children; pediatric assessment requires a clinician
- ✗Pregnant or breastfeeding women using standard TDEE or macro calculators — different formulas and professional guidance apply
- ✗People with or recovering from an eating disorder — calorie and macro tools can cause harm; please consult a registered dietitian or therapist first
How we build our calculators
Our editorial and engineering process, step by step. Read the full methodology →
STEP 01
Source a peer-reviewed formula
Every calculator starts with a named, citable equation from a primary source — WHO standards, NIH guidelines, Mifflin-St Jeor (1990), Harris-Benedict (revised 1984), U.S. Navy circumference method, ACSM exercise physiology, and similar. We do not invent coefficients.
STEP 02
Implement and unit-test the math
The formula is implemented in TypeScript with unit tests that validate known edge cases against published examples. Both metric and imperial units are supported, and rounding follows the conventions of the original paper.
STEP 03
Guideline alignment and validation
Before a calculator goes live, the math, copy, and interpretation ranges are cross-checked against current published guidelines. Anything ambiguous is flagged in plain English on the results page rather than hidden.
STEP 04
Accessibility and privacy check
Calculators are tested for keyboard navigation, screen-reader labels, and color contrast. All computation runs client-side in your browser — no form data is sent to our servers or any third party.
STEP 05
Plain-English interpretation
A raw number is rarely useful on its own. Every result is paired with a jargon-free explanation, a link to the source, a "consult a clinician" reminder, and practical context — never fear-mongering or upsells.
STEP 06
Scheduled re-review
Calculators are re-checked at least once a year against the latest published guidelines. When a reference body updates a threshold, we update the tool and note the change.
Trust & transparency
The promises and the limits — in the clearest language we can write.
What we do
- • Run every calculation in your browser — nothing is uploaded.
- • Cite a named, peer-reviewed source for every formula.
- • Publish our source code and revision history openly on GitHub.
- • Disclose any advertising or affiliate links clearly.
- • Fix reported bugs promptly and document changes.
- • Reply to every email from a real human (İsmail).
What we don't do
- • We do not sell, rent, or share your personal data.
- • We do not require accounts or email addresses.
- • We do not provide medical diagnosis or treatment.
- • We do not hide results behind a paywall.
- • We do not use dark patterns or fake urgency.
- • We do not publish AI-generated medical claims unchecked.
Medical disclaimer
HealthCalcPro is an educational lifestyle tool, not a medical device. The information it provides is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. See our full medical disclaimer.
Primary sources we rely on
The peer-reviewed and guideline references behind our calculators. Full formula documentation →
World Health Organization (WHO) ↗
BMI categories, child growth standards, global obesity thresholds
U.S. Centers for Disease Control (CDC) ↗
Adult BMI ranges, blood pressure categories, physical activity guidelines
National Institutes of Health (NIH / NHLBI) ↗
Obesity education, waist-to-hip ratio, cardiovascular risk factors
Mifflin-St Jeor equation (1990) ↗
Basal Metabolic Rate — the modern default for adult resting metabolic rate estimation
Harris-Benedict equation (revised 1984) ↗
Historical BMR formula, offered for comparison against Mifflin-St Jeor
U.S. Navy circumference method (Hodgdon & Beckett, 1984) ↗
Body fat percentage estimation — ±3-4% accuracy vs DEXA gold standard
American College of Sports Medicine (ACSM) ↗
Heart-rate training zones, exercise prescription, VO₂ max estimation
U.S. Dietary Guidelines for Americans ↗
Macronutrient ranges, calorie needs by age and activity level (HHS/USDA)
Frequently asked questions
The questions new visitors ask most often.
Is HealthCalcPro really free?+
Yes — every calculator, guide, quiz and dashboard is 100% free. We have no premium tier, no locked features, and no trial countdowns. The site is supported by light display ads and clearly-labeled affiliate links.
Do I need to create an account?+
No. We intentionally do not offer user accounts or email sign-ups. Everything works anonymously the moment you land on a calculator page. Your results stay in your browser.
Where does my data go when I use a calculator?+
Nowhere external. All math runs client-side in JavaScript. The numbers you enter are never sent to our servers, never stored in a database, and never shared with third parties. The optional Health Dashboard saves results to your browser's localStorage only — it stays on your device.
Are your calculators a substitute for seeing a doctor?+
No. They are educational lifestyle tools. A BMI or TDEE number can be a useful starting point for a conversation with your physician, dietitian, or trainer — but it cannot diagnose a condition or prescribe treatment. If a result concerns you, please consult a qualified professional.
Who writes and reviews the content?+
Calculators and editorial content are built by İsmail Günaydın (founder) and cross-checked against primary peer-reviewed guidelines before publication. We cite every source and document the formula used.
How do you make money if everything is free?+
HealthCalcPro is supported by programmatic display advertising and a small number of clearly-labeled affiliate links (fitness equipment, books). We never let advertisers influence the math or editorial content.
I found a bug or a wrong result. What do I do?+
Please email us via the contact page. Accuracy is the entire point of the site; bug reports go to the top of the queue.
By the numbers
12+
Peer-reviewed calculators
16
Sites in the portfolio
11+
Books published by founder
100%
Free, no paywall, forever
Part of a wider network
HealthCalcPro is one of 17 digital brands built and operated by the same founder — same privacy model, same source-citing standards across all sites.
Hepsi Hesapla ↗
Financial, mathematical and everyday calculators — all in one place.
hepsihesapla.com
Unit Convert Now ↗
Instant unit conversions for length, weight, temperature, currency and more.
unitconvertnow.com
Text Word Count ↗
Free online word, character and reading time counter for writers.
textwordcount.com
Toolgenx ↗
Productivity utilities and generators for creators and developers.
toolgenx.com
Pix n PDF ↗
Convert, compress and edit images and PDF files online — no install.
pixnpdf.com
Wheelie Names ↗
Random name picker wheel for classrooms, giveaways and decisions.
wheelienames.com
Modern Web SEO ↗
Modern SEO and GEO strategies for AI-first search visibility.
modernwebseo.com
A1 Organizasyon ↗
Wedding, engagement and special event planning services.
a1organizasyon.com
Luna Intim ↗
Premium lingerie and personal care collection.
lunaintim.com
Sauna Kabin ↗
Sauna cabin sales and installation for homes and businesses.
saunakabin.com
Trio Lezzet ↗
Delicious recipes and food culture platform.
triolezzet.com
Işıklı Tabela ↗
Custom illuminated signage manufacturing and installation services.
isiklitabela.net
Tabela TR ↗
Nationwide signage production, design and installation company in Turkey.
tabelatr.com
Yılbaşı Işık Süsleme ↗
Illuminated decoration and lighting services for New Year and special occasions.
yilbasiisiksusleme.com
Işıklı Süsleme ↗
Decorative lighting and illuminated décor for events, venues and homes.
isiklisusleme.com
İsmail Günaydın ↗
Founder portfolio — projects, writing and contact.
ismailgunaydin.com
Official resources & channels
Verified places where HealthCalcPro and its founder publish work.
Start exploring
Browse the calculators, read the methodology, or check the editorial policy to understand exactly what we do — and what we don't.
This page was last reviewed and updated on . See the public commit history for every change.